ggml : introduce bfloat16 support (llama/6412)

* Introduce bfloat16 support

Many models on Hugging Face (e.g. Mistral, TinyLLaMA) use bfloat16 as
their canonical floating point format.

┌sign
│
│ ┌exponent
│ │
│ │ ┌mantissa
│ │ │
│┌──┴───┐┌─┴───┐
0b0000000000000000 brain16

This encoding has the same number of exponent bits as float32. That
makes conversion relatively straightforward, even in the absence of
hardware support. For example, converting brain16 to binary32 means
simply shifting 16 bits to the left.

┌sign
│
│ ┌exponent
│ │
│ │ ┌mantissa
│ │ │
│┌──┴───┐┌─┴───────────────────┐
0b00000000000000000000000000000000 IEEE binary32

The issue is that converting bf16 to fp16 can result in information
loss. Only 13% of bf16 numbers can be precisely represented in fp16
which in practice ends up being 99.71% of Mistral 7b v0.2's weights
however there is currently no way other than fp32 to get the others

┌sign
│
│ ┌exponent
│ │
│ │ ┌mantissa
│ │ │
│┌─┴─┐┌─┴──────┐
0b0000000000000000 IEEE binary16

This change fixes that, by adding a bf16 data type to GGML. Support
for CPU inference has been implemented along with optimizations for
the AVX2, AVX512, and AVX512BF16 ISAs. Perplexity on Mistral 7b 0.2
improves somewhere around -0.0024 to -0.0046 compared to using fp16

* Remove GGML code that's not needed

* Minimize the GGML API surface area for BF16

* Remove bf16 luts

* Make the GGML header look nicer

* Fix documentation

* Apply ggerganov's fixes for test-backend-ops

* Add BF16 code for new ggml_validate_row_data() function

ggml-impl.h

@@ -17,6 +17,83 @@
 #define MIN(a, b) ((a) < (b) ? (a) : (b))
 #define MAX(a, b) ((a) > (b) ? (a) : (b))
 
+/**
+ * Converts brain16 to float32.
+ *
+ * The bfloat16 floating point format has the following structure:
+ *
+ *       ┌sign
+ *       │
+ *       │   ┌exponent
+ *       │   │
+ *       │   │      ┌mantissa
+ *       │   │      │
+ *       │┌──┴───┐┌─┴───┐
+ *     0b0000000000000000 brain16
+ *
+ * Since bf16 has the same number of exponent bits as a 32bit float,
+ * encoding and decoding numbers becomes relatively straightforward.
+ *
+ *       ┌sign
+ *       │
+ *       │   ┌exponent
+ *       │   │
+ *       │   │      ┌mantissa
+ *       │   │      │
+ *       │┌──┴───┐┌─┴───────────────────┐
+ *     0b00000000000000000000000000000000 IEEE binary32
+ *
+ * For comparison, the standard fp16 format has fewer exponent bits.
+ *
+ *       ┌sign
+ *       │
+ *       │  ┌exponent
+ *       │  │
+ *       │  │    ┌mantissa
+ *       │  │    │
+ *       │┌─┴─┐┌─┴──────┐
+ *     0b0000000000000000 IEEE binary16
+ *
+ * @see IEEE 754-2008
+ */
+static inline float ggml_compute_bf16_to_fp32(ggml_bf16_t h) {
+    union {
+        float f;
+        uint32_t i;
+    } u;
+    u.i = (uint32_t)h.bits << 16;
+    return u.f;
+}
+
+/**
+ * Converts float32 to brain16.
+ *
+ * This function is binary identical to AMD Zen4 VCVTNEPS2BF16.
+ * Subnormals shall be flushed to zero, and NANs will be quiet.
+ * This code should vectorize nicely if using modern compilers.
+ */
+static inline ggml_bf16_t ggml_compute_fp32_to_bf16(float s) {
+    ggml_bf16_t h;
+    union {
+        float f;
+        uint32_t i;
+    } u;
+    u.f = s;
+    if ((u.i & 0x7fffffff) > 0x7f800000) { /* nan */
+        h.bits = (u.i >> 16) | 64; /* force to quiet */
+        return h;
+    }
+    if (!(u.i & 0x7f800000)) { /* subnormal */
+        h.bits = (u.i & 0x80000000) >> 16; /* flush to zero */
+        return h;
+    }
+    h.bits = (u.i + (0x7fff + ((u.i >> 16) & 1))) >> 16;
+    return h;
+}
+
+#define GGML_FP32_TO_BF16(x) ggml_compute_fp32_to_bf16(x)
+#define GGML_BF16_TO_FP32(x) ggml_compute_bf16_to_fp32(x)
+
 #ifdef __cplusplus
 extern "C" {
 #endif

ggml-metal.m

@@ -806,7 +806,7 @@ static bool ggml_metal_supports_op(const struct ggml_metal_context * ctx, const
         case GGML_OP_DIAG_MASK_INF:
         case GGML_OP_GET_ROWS:
             {
-                return op->ne[3] == 1;
+                return op->src[0]->type != GGML_TYPE_BF16 && op->ne[3] == 1;
             }
         default:
             return false;

ggml-quants.c

@@ -12456,6 +12456,24 @@ bool ggml_validate_row_data(enum ggml_type type, const void * data, size_t nbyte
     const size_t nb = nbytes/ggml_type_size(type);
 
     switch (type) {
+        case GGML_TYPE_BF16:
+            {
+                int nans = 0;
+                int infs = 0;
+                const unsigned short * f = (const unsigned short *) data;
+                for (size_t i = 0; i < nb; ++i) {
+                    nans += (f[i] & 0x7fff) > 0x7f80;
+                    infs += (f[i] & 0x7fff) == 0x7f80;
+                }
+                if (nans) {
+                    fprintf(stderr, "%s: found %d NaNs in row of %zu BF16 values\n", __func__, nans, nb);
+                    return false;
+                }
+                if (infs) {
+                    fprintf(stderr, "%s: found %d infinities in row of %zu BF16 values\n", __func__, infs, nb);
+                    return false;
+                }
+            } break;
         case GGML_TYPE_F16:
             {
                 const ggml_fp16_t * f = (const ggml_fp16_t *) data;

ggml.c

@@ -322,7 +322,7 @@ static ggml_fp16_t ggml_table_exp_f16[1 << 16];
 // precomputed f32 table for f16 (256 KB) (ggml-impl.h)
 float ggml_table_f32_f16[1 << 16];
 
-const char * ggml_status_to_string(enum ggml_status status) {
+GGML_CALL const char * ggml_status_to_string(enum ggml_status status) {
     switch (status) {
         case GGML_STATUS_ALLOC_FAILED: return "GGML status: error (failed to allocate memory)";
         case GGML_STATUS_FAILED:       return "GGML status: error (operation failed)";
@@ -333,16 +333,26 @@ const char * ggml_status_to_string(enum ggml_status status) {
     return "GGML status: unknown";
 }
 
-// note: do not use these inside ggml.c
-// these are meant to be used via the ggml.h API
 float ggml_fp16_to_fp32(ggml_fp16_t x) {
+#define ggml_fp16_to_fp32 do_not_use__ggml_fp16_to_fp32__in_ggml
     return GGML_FP16_TO_FP32(x);
 }
 
 ggml_fp16_t ggml_fp32_to_fp16(float x) {
+#define ggml_fp32_to_fp16 do_not_use__ggml_fp32_to_fp16__in_ggml
     return GGML_FP32_TO_FP16(x);
 }
 
+float ggml_bf16_to_fp32(ggml_bf16_t x) {
+#define ggml_bf16_to_fp32 do_not_use__ggml_bf16_to_fp32__in_ggml
+    return GGML_BF16_TO_FP32(x);  // it just left shifts
+}
+
+ggml_bf16_t ggml_fp32_to_bf16(float x) {
+#define ggml_fp32_to_bf16 do_not_use__ggml_fp32_to_bf16__in_ggml
+    return GGML_FP32_TO_BF16(x);
+}
+
 void ggml_fp16_to_fp32_row(const ggml_fp16_t * x, float * y, int64_t n) {
     for (int64_t i = 0; i < n; i++) {
         y[i] = GGML_FP16_TO_FP32(x[i]);
@@ -368,6 +378,49 @@ void ggml_fp32_to_fp16_row(const float * x, ggml_fp16_t * y, int64_t n) {
     }
 }
 
+void ggml_bf16_to_fp32_row(const ggml_bf16_t * x, float * y, int64_t n) {
+    int64_t i = 0;
+#if defined(__AVX512F__)
+    for (; i + 16 <= n; i += 16) {
+        _mm512_storeu_ps(y + i,
+                         _mm512_castsi512_ps(
+                             _mm512_slli_epi32(
+                                 _mm512_cvtepu16_epi32(
+                                     _mm256_loadu_si256(
+                                         (const __m256i *)(x + i))),
+                                 16)));
+    }
+#elif defined(__AVX2__)
+    for (; i + 8 <= n; i += 8) {
+        _mm256_storeu_ps(y + i,
+                         _mm256_castsi256_ps(
+                             _mm256_slli_epi32(
+                                 _mm256_cvtepu16_epi32(
+                                     _mm_loadu_si128(
+                                         (const __m128i *)(x + i))),
+                                 16)));
+    }
+#endif
+    for (; i < n; i++) {
+        y[i] = GGML_BF16_TO_FP32(x[i]);
+    }
+}
+
+void ggml_fp32_to_bf16_row(const float * x, ggml_bf16_t * y, int64_t n) {
+  int i = 0;
+#if defined(__AVX512BF16__)
+  for (; i + 32 <= n; i += 32) {
+        _mm512_storeu_ps(
+            (__m512 *)(y + i),
+            (__m512)_mm512_cvtne2ps_pbh(_mm512_loadu_ps(x + i + 16),
+                                        _mm512_loadu_ps(x + i)));
+  }
+#endif
+    for (; i < n; i++) {
+        y[i] = GGML_FP32_TO_BF16(x[i]);
+    }
+}
+
 bool ggml_guid_matches(ggml_guid_t guid_a, ggml_guid_t guid_b) {
     return memcmp(guid_a, guid_b, sizeof(ggml_guid)) == 0;
 }
@@ -503,6 +556,7 @@ static const size_t CACHE_LINE_SIZE_F32 = CACHE_LINE_SIZE/sizeof(float);
 
 static void ggml_vec_dot_f32(int n, float * restrict s, size_t bs, const float * restrict x, size_t bx, const float * restrict y, size_t by, int nrc);
 static void ggml_vec_dot_f16(int n, float * restrict s, size_t bs, ggml_fp16_t * restrict x, size_t bx, ggml_fp16_t * restrict y, size_t by, int nrc);
+static void ggml_vec_dot_bf16(int n, float * restrict s, size_t bs, ggml_bf16_t * restrict x, size_t bx, ggml_bf16_t * restrict y, size_t by, int nrc);
 
 static const ggml_type_traits_t type_traits[GGML_TYPE_COUNT] = {
     [GGML_TYPE_I8] = {
@@ -845,6 +899,18 @@ static const ggml_type_traits_t type_traits[GGML_TYPE_COUNT] = {
         .type_size                = sizeof(block_q8_K),
         .is_quantized             = true,
         .from_float               = quantize_row_q8_K,
+    },
+    [GGML_TYPE_BF16] = {
+        .type_name                = "bf16",
+        .blck_size                = 1,
+        .type_size                = sizeof(ggml_bf16_t),
+        .is_quantized             = false,
+        .to_float                 = (ggml_to_float_t) ggml_bf16_to_fp32_row,
+        .from_float               = (ggml_from_float_t) ggml_fp32_to_bf16_row,
+        .from_float_reference     = (ggml_from_float_t) ggml_fp32_to_bf16_row,
+        .vec_dot                  = (ggml_vec_dot_t) ggml_vec_dot_bf16,
+        .vec_dot_type             = GGML_TYPE_BF16,
+        .nrows                    = 1,
     }
 };
 
@@ -1480,6 +1546,8 @@ inline static void ggml_vec_set_i32(const int n, int32_t * x, const int32_t v) {
 
 inline static void ggml_vec_set_f16(const int n, ggml_fp16_t * x, const int32_t v) { for (int i = 0; i < n; ++i) x[i] = v; }
 
+inline static void ggml_vec_set_bf16(const int n, ggml_bf16_t * x, const ggml_bf16_t v) { for (int i = 0; i < n; ++i) x[i] = v; }
+
 inline static void ggml_vec_add_f32 (const int n, float * z, const float * x, const float * y) { for (int i = 0; i < n; ++i) z[i]  = x[i] + y[i]; }
 inline static void ggml_vec_add1_f32(const int n, float * z, const float * x, const float   v) { for (int i = 0; i < n; ++i) z[i]  = x[i] + v;    }
 inline static void ggml_vec_acc_f32 (const int n, float * y, const float * x)                  { for (int i = 0; i < n; ++i) y[i] += x[i];        }
@@ -1498,7 +1566,7 @@ static void ggml_vec_dot_f32(int n, float * restrict s, size_t bs, const float *
    UNUSED(by);
    UNUSED(bs);
 
-#ifdef GGML_SIMD
+#if defined(GGML_SIMD)
     float sumf = 0.0f;
     const int np = (n & ~(GGML_F32_STEP - 1));
 
@@ -1534,6 +1602,70 @@ static void ggml_vec_dot_f32(int n, float * restrict s, size_t bs, const float *
     *s = sumf;
 }
 
+static void ggml_vec_dot_bf16(int n, float * restrict s, size_t bs, ggml_bf16_t * restrict x, size_t bx, ggml_bf16_t * restrict y, size_t by, int nrc) {
+    assert(nrc == 1);
+    UNUSED(nrc);
+    UNUSED(bx);
+    UNUSED(by);
+    UNUSED(bs);
+    int i = 0;
+    ggml_float sumf = 0;
+
+#if defined(__AVX512BF16__)
+    __m512 c1 = _mm512_setzero_ps();
+    __m512 c2 = _mm512_setzero_ps();
+    for (; i + 64 <= n; i += 64) {
+        c1 = _mm512_dpbf16_ps(c1, (__m512bh)_mm512_loadu_ps((const float *)(x + i)),
+                              (__m512bh)_mm512_loadu_ps((const float *)(y + i)));
+        c2 = _mm512_dpbf16_ps(c2, (__m512bh)_mm512_loadu_ps((const float *)(x + i + 32)),
+                              (__m512bh)_mm512_loadu_ps((const float *)(y + i + 32)));
+    }
+    sumf += (ggml_float)_mm512_reduce_add_ps(c1);
+    sumf += (ggml_float)_mm512_reduce_add_ps(c2);
+
+#elif defined(__AVX512F__)
+#define LOAD(p) _mm512_castsi512_ps(_mm512_slli_epi32(_mm512_cvtepu16_epi32(_mm256_loadu_si256((const __m256i *)(p))), 16))
+    __m512 c1 = _mm512_setzero_ps();
+    __m512 c2 = _mm512_setzero_ps();
+    for (; i + 32 <= n; i += 32) {
+        c1 = _mm512_add_ps(_mm512_mul_ps(LOAD(x + i), LOAD(y + i)), c1);
+        c2 = _mm512_add_ps(_mm512_mul_ps(LOAD(x + i + 16), LOAD(y + i + 16)), c2);
+    }
+    sumf += (ggml_float)_mm512_reduce_add_ps(c1);
+    sumf += (ggml_float)_mm512_reduce_add_ps(c2);
+
+#undef LOAD
+#elif defined(__AVX2__)
+#define LOAD(p) _mm256_castsi256_ps(_mm256_slli_epi32(_mm256_cvtepu16_epi32(_mm_loadu_si128((const __m128i *)(p))), 16))
+    __m256 c1 = _mm256_setzero_ps();
+    __m256 c2 = _mm256_setzero_ps();
+    __m256 c3 = _mm256_setzero_ps();
+    __m256 c4 = _mm256_setzero_ps();
+    for (; i + 32 <= n; i += 32) {
+        c1 = _mm256_add_ps(_mm256_mul_ps(LOAD(x + i), LOAD(y + i)), c1);
+        c2 = _mm256_add_ps(_mm256_mul_ps(LOAD(x + i + 8), LOAD(y + i + 8)), c2);
+        c3 = _mm256_add_ps(_mm256_mul_ps(LOAD(x + i + 16), LOAD(y + i + 16)), c3);
+        c4 = _mm256_add_ps(_mm256_mul_ps(LOAD(x + i + 24), LOAD(y + i + 24)), c4);
+    }
+    __m128 g;
+    c1 = _mm256_add_ps(_mm256_add_ps(c1, c3),
+                       _mm256_add_ps(c2, c4));
+    g = _mm_add_ps(_mm256_extractf128_ps(c1, 1),
+                   _mm256_castps256_ps128(c1));
+    g = _mm_add_ps(g, _mm_movehl_ps(g, g));
+    g = _mm_add_ss(g, _mm_movehdup_ps(g));
+    sumf += (ggml_float)_mm_cvtss_f32(g);
+
+#undef LOAD
+#endif
+
+    for (; i < n; ++i) {
+        sumf += (ggml_float)(GGML_BF16_TO_FP32(x[i]) *
+                             GGML_BF16_TO_FP32(y[i]));
+    }
+    *s = sumf;
+}
+
 static void ggml_vec_dot_f16(int n, float * restrict s, size_t bs, ggml_fp16_t * restrict x, size_t bx, ggml_fp16_t * restrict y, size_t by, int nrc) {
     assert(nrc == 1);
     UNUSED(nrc);
@@ -1968,6 +2100,14 @@ inline static void ggml_vec_sum_f16_ggf(const int n, float * s, const ggml_fp16_
     *s = sum;
 }
 
+inline static void ggml_vec_sum_bf16_ggf(const int n, float * s, const ggml_bf16_t * x) {
+    float sum = 0.0f;
+    for (int i = 0; i < n; ++i) {
+        sum += GGML_BF16_TO_FP32(x[i]);
+    }
+    *s = sum;
+}
+
 inline static void ggml_vec_max_f32(const int n, float * s, const float * x) {
 #ifndef GGML_USE_ACCELERATE
     float max = -INFINITY;
@@ -2379,7 +2519,7 @@ void ggml_numa_init(enum ggml_numa_strategy numa_flag) {
     // figure out which node we're on
     uint current_cpu;
     int getcpu_ret = 0;
-#if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 28)
+#if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 28) || defined(__COSMOPOLITAN__)
     getcpu_ret = getcpu(&current_cpu, &g_state.numa.current_node);
 #else
     // old glibc doesn't have a wrapper for this call. Fall back on direct syscall
@@ -2590,6 +2730,7 @@ enum ggml_type ggml_ftype_to_ggml_type(enum ggml_ftype ftype) {
     switch (ftype) {
         case GGML_FTYPE_ALL_F32:              wtype = GGML_TYPE_F32;   break;
         case GGML_FTYPE_MOSTLY_F16:           wtype = GGML_TYPE_F16;   break;
+        case GGML_FTYPE_MOSTLY_BF16:          wtype = GGML_TYPE_BF16;  break;
         case GGML_FTYPE_MOSTLY_Q4_0:          wtype = GGML_TYPE_Q4_0;  break;
         case GGML_FTYPE_MOSTLY_Q4_1:          wtype = GGML_TYPE_Q4_1;  break;
         case GGML_FTYPE_MOSTLY_Q5_0:          wtype = GGML_TYPE_Q5_0;  break;
@@ -2731,15 +2872,16 @@ struct ggml_context * ggml_init(struct ggml_init_params params) {
         {
             const uint64_t t_start = ggml_time_us(); UNUSED(t_start);
 
-            ggml_fp16_t ii;
             for (int i = 0; i < (1 << 16); ++i) {
-                uint16_t ui = i;
-                memcpy(&ii, &ui, sizeof(ii));
-                const float f = ggml_table_f32_f16[i] = GGML_COMPUTE_FP16_TO_FP32(ii);
+                union {
+                    uint16_t u16;
+                    ggml_fp16_t fp16;
+                } u = {i};
+                float f = ggml_table_f32_f16[i] = GGML_COMPUTE_FP16_TO_FP32(u.fp16);
                 ggml_table_gelu_f16[i] = GGML_FP32_TO_FP16(ggml_gelu_f32(f));
                 ggml_table_gelu_quick_f16[i] = GGML_FP32_TO_FP16(ggml_gelu_quick_f32(f));
                 ggml_table_silu_f16[i] = GGML_FP32_TO_FP16(ggml_silu_f32(f));
-                ggml_table_exp_f16[i]  = GGML_FP32_TO_FP16(expf(f));
+                ggml_table_exp_f16[i] = GGML_FP32_TO_FP16(expf(f));
             }
 
             const uint64_t t_end = ggml_time_us(); UNUSED(t_end);
@@ -3203,6 +3345,13 @@ struct ggml_tensor * ggml_set_i32 (struct ggml_tensor * tensor, int32_t value) {
                     ggml_vec_set_f16(nc, (ggml_fp16_t *)(data + i*n1), GGML_FP32_TO_FP16(value));
                 }
             } break;
+        case GGML_TYPE_BF16:
+            {
+                assert(tensor->nb[0] == sizeof(ggml_fp16_t));
+                for (int i = 0; i < n; i++) {
+                    ggml_vec_set_bf16(nc, (ggml_bf16_t *)(data + i*n1), GGML_FP32_TO_BF16(value));
+                }
+            } break;
         case GGML_TYPE_F32:
             {
                 assert(tensor->nb[0] == sizeof(float));
@@ -3255,6 +3404,13 @@ struct ggml_tensor * ggml_set_f32(struct ggml_tensor * tensor, float value) {
                     ggml_vec_set_f16(nc, (ggml_fp16_t *)(data + i*n1), GGML_FP32_TO_FP16(value));
                 }
             } break;
+        case GGML_TYPE_BF16:
+            {
+                assert(tensor->nb[0] == sizeof(ggml_bf16_t));
+                for (int i = 0; i < n; i++) {
+                    ggml_vec_set_bf16(nc, (ggml_bf16_t *)(data + i*n1), GGML_FP32_TO_BF16(value));
+                }
+            } break;
         case GGML_TYPE_F32:
             {
                 assert(tensor->nb[0] == sizeof(float));
@@ -3322,6 +3478,11 @@ int32_t ggml_get_i32_1d(const struct ggml_tensor * tensor, int i) {
                 GGML_ASSERT(tensor->nb[0] == sizeof(ggml_fp16_t));
                 return GGML_FP16_TO_FP32(((ggml_fp16_t *)(tensor->data))[i]);
             }
+        case GGML_TYPE_BF16:
+            {
+                GGML_ASSERT(tensor->nb[0] == sizeof(ggml_bf16_t));
+                return GGML_BF16_TO_FP32(((ggml_bf16_t *)(tensor->data))[i]);
+            }
         case GGML_TYPE_F32:
             {
                 GGML_ASSERT(tensor->nb[0] == sizeof(float));
@@ -3364,6 +3525,11 @@ void ggml_set_i32_1d(const struct ggml_tensor * tensor, int i, int32_t value) {
                 GGML_ASSERT(tensor->nb[0] == sizeof(ggml_fp16_t));
                 ((ggml_fp16_t *)(tensor->data))[i] = GGML_FP32_TO_FP16(value);
             } break;
+        case GGML_TYPE_BF16:
+            {
+                GGML_ASSERT(tensor->nb[0] == sizeof(ggml_bf16_t));
+                ((ggml_bf16_t *)(tensor->data))[i] = GGML_FP32_TO_BF16(value);
+            } break;
         case GGML_TYPE_F32:
             {
                 GGML_ASSERT(tensor->nb[0] == sizeof(float));
@@ -3387,6 +3553,8 @@ int32_t ggml_get_i32_nd(const struct ggml_tensor * tensor, int i0, int i1, int i
             return ((int32_t *) data)[0];
         case GGML_TYPE_F16:
             return GGML_FP16_TO_FP32(((ggml_fp16_t *) data)[0]);
+        case GGML_TYPE_BF16:
+            return GGML_BF16_TO_FP32(((ggml_bf16_t *) data)[0]);
         case GGML_TYPE_F32:
             return ((float *) data)[0];
         default:
@@ -3415,6 +3583,10 @@ void ggml_set_i32_nd(const struct ggml_tensor * tensor, int i0, int i1, int i2,
             {
                 ((ggml_fp16_t *)(data))[0] = GGML_FP32_TO_FP16(value);
             } break;
+        case GGML_TYPE_BF16:
+            {
+                ((ggml_bf16_t *)(data))[0] = GGML_FP32_TO_BF16(value);
+            } break;
         case GGML_TYPE_F32:
             {
                 ((float *)(data))[0] = value;
@@ -3453,6 +3625,11 @@ float ggml_get_f32_1d(const struct ggml_tensor * tensor, int i) {
                 GGML_ASSERT(tensor->nb[0] == sizeof(ggml_fp16_t));
                 return GGML_FP16_TO_FP32(((ggml_fp16_t *)(tensor->data))[i]);
             }
+        case GGML_TYPE_BF16:
+            {
+                GGML_ASSERT(tensor->nb[0] == sizeof(ggml_bf16_t));
+                return GGML_BF16_TO_FP32(((ggml_bf16_t *)(tensor->data))[i]);
+            }
         case GGML_TYPE_F32:
             {
                 GGML_ASSERT(tensor->nb[0] == sizeof(float));
@@ -3495,6 +3672,11 @@ void ggml_set_f32_1d(const struct ggml_tensor * tensor, int i, float value) {
                 GGML_ASSERT(tensor->nb[0] == sizeof(ggml_fp16_t));
                 ((ggml_fp16_t *)(tensor->data))[i] = GGML_FP32_TO_FP16(value);
             } break;
+        case GGML_TYPE_BF16:
+            {
+                GGML_ASSERT(tensor->nb[0] == sizeof(ggml_bf16_t));
+                ((ggml_bf16_t *)(tensor->data))[i] = GGML_FP32_TO_BF16(value);
+            } break;
         case GGML_TYPE_F32:
             {
                 GGML_ASSERT(tensor->nb[0] == sizeof(float));
@@ -3518,6 +3700,8 @@ float ggml_get_f32_nd(const struct ggml_tensor * tensor, int i0, int i1, int i2,
             return ((int32_t *) data)[0];
         case GGML_TYPE_F16:
             return GGML_FP16_TO_FP32(((ggml_fp16_t *) data)[0]);
+        case GGML_TYPE_BF16:
+            return GGML_BF16_TO_FP32(((ggml_bf16_t *) data)[0]);
         case GGML_TYPE_F32:
             return ((float *) data)[0];
         default:
@@ -3546,6 +3730,10 @@ void ggml_set_f32_nd(const struct ggml_tensor * tensor, int i0, int i1, int i2,
             {
                 ((ggml_fp16_t *)(data))[0] = GGML_FP32_TO_FP16(value);
             } break;
+        case GGML_TYPE_BF16:
+            {
+                ((ggml_bf16_t *)(data))[0] = GGML_FP32_TO_BF16(value);
+            } break;
         case GGML_TYPE_F32:
             {
                 ((float *)(data))[0] = value;
@@ -3740,7 +3928,11 @@ static struct ggml_tensor * ggml_add_cast_impl(
     // TODO: support less-strict constraint
     //       GGML_ASSERT(ggml_can_repeat(b, a));
     GGML_ASSERT(ggml_can_repeat_rows(b, a));
-    GGML_ASSERT(ggml_is_quantized(a->type) || a->type == GGML_TYPE_F16); // currently only supported for quantized input and f16
+
+    // currently only supported for quantized input and f16
+    GGML_ASSERT(ggml_is_quantized(a->type) ||
+                a->type == GGML_TYPE_F16 ||
+                a->type == GGML_TYPE_BF16);
 
     bool is_node = false;
 
@@ -7231,8 +7423,8 @@ static void ggml_compute_forward_dup_same_cont(
             ((char *) src0->data + ie0*nb00),
             (ie1 - ie0) * ggml_type_size(src0->type));
     }
-
 }
+
 static void ggml_compute_forward_dup_f16(
         const struct ggml_compute_params * params,
         struct ggml_tensor * dst) {
@@ -7506,7 +7698,7 @@ static void ggml_compute_forward_dup_f16(
     }
 }
 
-static void ggml_compute_forward_dup_f32(
+static void ggml_compute_forward_dup_bf16(
         const struct ggml_compute_params * params,
         struct ggml_tensor * dst) {
 
@@ -7554,10 +7746,11 @@ static void ggml_compute_forward_dup_f32(
         return;
     }
 
+    // TODO: add more special-case implementations for tensor shapes/strides that can benefit from memcpy
+
     if (ggml_is_contiguous(dst)) {
-        // TODO: simplify
-        if (nb00 == sizeof(float)) {
-            if (dst->type == GGML_TYPE_F32) {
+        if (nb00 == sizeof(ggml_bf16_t)) {
+            if (dst->type == GGML_TYPE_BF16) {
                 size_t id = 0;
                 const size_t rs = ne00 * nb00;
                 char * dst_ptr = (char *) dst->data;
@@ -7573,8 +7766,43 @@ static void ggml_compute_forward_dup_f32(
                         id += rs * (ne01 - ir1);
                     }
                 }
+            } else if (dst->type == GGML_TYPE_F16) {
+                size_t id = 0;
+                ggml_fp16_t * dst_ptr = (ggml_fp16_t *) dst->data;
+
+                for (int i03 = 0; i03 < ne03; i03++) {
+                    for (int i02 = 0; i02 < ne02; i02++) {
+                        id += ne00 * ir0;
+                        for (int i01 = ir0; i01 < ir1; i01++) {
+                            const ggml_bf16_t * src0_ptr = (ggml_bf16_t *) ((char *) src0->data + i01*nb01 + i02*nb02 + i03*nb03);
+                            for (int i00 = 0; i00 < ne00; i00++) {
+                                dst_ptr[id] = GGML_FP32_TO_FP16(GGML_BF16_TO_FP32(src0_ptr[i00]));
+                                id++;
+                            }
+                        }
+                        id += ne00 * (ne01 - ir1);
+                    }
+                }
+            } else if (dst->type == GGML_TYPE_F32) {
+                size_t id = 0;
+                float * dst_ptr = (float *) dst->data;
+
+                for (int i03 = 0; i03 < ne03; i03++) {
+                    for (int i02 = 0; i02 < ne02; i02++) {
+                        id += ne00 * ir0;
+                        for (int i01 = ir0; i01 < ir1; i01++) {
+                            const ggml_bf16_t * src0_ptr = (ggml_bf16_t *) ((char *) src0->data + i01*nb01 + i02*nb02 + i03*nb03);
+                            for (int i00 = 0; i00 < ne00; i00++) {
+                                dst_ptr[id] = GGML_BF16_TO_FP32(src0_ptr[i00]);
+                                id++;
+                            }
+                        }
+                        id += ne00 * (ne01 - ir1);
+                    }
+                }
             } else if (type_traits[dst->type].from_float) {
                 ggml_from_float_t const quantize_row_q = type_traits[dst->type].from_float;
+                float * src0_f32 = (float *) params->wdata + (ne00 + CACHE_LINE_SIZE_F32) * ith;
 
                 size_t id = 0;
                 size_t rs = nb0 * (ne00 / ggml_blck_size(dst->type));
@@ -7584,8 +7812,13 @@ static void ggml_compute_forward_dup_f32(
                     for (int i02 = 0; i02 < ne02; i02++) {
                         id += rs * ir0;
                         for (int i01 = ir0; i01 < ir1; i01++) {
-                            const float * src0_ptr = (float *) ((char *) src0->data + i01*nb01 + i02*nb02 + i03*nb03);
-                            quantize_row_q(src0_ptr, dst_ptr + id, ne00);
+                            const ggml_bf16_t * src0_ptr = (ggml_bf16_t *) ((char *) src0->data + i01*nb01 + i02*nb02 + i03*nb03);
+
+                            for (int i00 = 0; i00 < ne00; i00++) {
+                                src0_f32[i00] = GGML_BF16_TO_FP32(src0_ptr[i00]);
+                            }
+
+                            quantize_row_q(src0_f32, dst_ptr + id, ne00);
                             id += rs;
                         }
                         id += rs * (ne01 - ir1);
@@ -7606,7 +7839,25 @@ static void ggml_compute_forward_dup_f32(
                         id += ne00 * ir0;
                         for (int i01 = ir0; i01 < ir1; i01++) {
                             for (int i00 = 0; i00 < ne00; i00++) {
-                                const float * src0_ptr = (float *) ((char *) src0->data + i00*nb00 + i01*nb01 + i02*nb02 + i03*nb03);
+                                const ggml_bf16_t * src0_ptr = (ggml_bf16_t *) ((char *) src0->data + i00*nb00 + i01*nb01 + i02*nb02 + i03*nb03);
+
+                                dst_ptr[id] = GGML_BF16_TO_FP32(*src0_ptr);
+                                id++;
+                            }
+                        }
+                        id += ne00 * (ne01 - ir1);
+                    }
+                }
+            } else if (dst->type == GGML_TYPE_BF16) {
+                size_t id = 0;
+                ggml_bf16_t * dst_ptr = (ggml_bf16_t *) dst->data;
+
+                for (int i03 = 0; i03 < ne03; i03++) {
+                    for (int i02 = 0; i02 < ne02; i02++) {
+                        id += ne00 * ir0;
+                        for (int i01 = ir0; i01 < ir1; i01++) {
+                            for (int i00 = 0; i00 < ne00; i00++) {
+                                const ggml_bf16_t * src0_ptr = (ggml_bf16_t *) ((char *) src0->data + i00*nb00 + i01*nb01 + i02*nb02 + i03*nb03);
 
                                 dst_ptr[id] = *src0_ptr;
                                 id++;
@@ -7624,9 +7875,9 @@ static void ggml_compute_forward_dup_f32(
                         id += ne00 * ir0;
                         for (int i01 = ir0; i01 < ir1; i01++) {
                             for (int i00 = 0; i00 < ne00; i00++) {
-                                const float * src0_ptr = (float *) ((char *) src0->data + i00*nb00 + i01*nb01 + i02*nb02 + i03*nb03);
+                                const ggml_bf16_t * src0_ptr = (ggml_bf16_t *) ((char *) src0->data + i00*nb00 + i01*nb01 + i02*nb02 + i03*nb03);
 
-                                dst_ptr[id] = GGML_FP32_TO_FP16(*src0_ptr);
+                                dst_ptr[id] = GGML_FP32_TO_FP16(GGML_BF16_TO_FP32(*src0_ptr));
                                 id++;
                             }
                         }
@@ -7637,18 +7888,16 @@ static void ggml_compute_forward_dup_f32(
                 GGML_ASSERT(false); // TODO: implement
             }
         }
-
         return;
     }
 
     // dst counters
-
     int64_t i10 = 0;
     int64_t i11 = 0;
     int64_t i12 = 0;
     int64_t i13 = 0;
 
-    if (dst->type == GGML_TYPE_F32) {
+    if (dst->type == GGML_TYPE_BF16) {
         for (int64_t i03 = 0; i03 < ne03; i03++) {
             for (int64_t i02 = 0; i02 < ne02; i02++) {
                 i10 += ne00 * ir0;
@@ -7669,7 +7918,59 @@ static void ggml_compute_forward_dup_f32(
                         const char * src0_ptr = ((char *) src0->data + i00*nb00 + i01*nb01 + i02*nb02 + i03*nb03);
                               char * dst_ptr  = ((char *)  dst->data + i10*nb0  + i11*nb1  + i12*nb2  + i13*nb3);
 
-                        memcpy(dst_ptr, src0_ptr, sizeof(float));
+                        memcpy(dst_ptr, src0_ptr, sizeof(ggml_bf16_t));
+
+                        if (++i10 == ne00) {
+                            i10 = 0;
+                            if (++i11 == ne01) {
+                                i11 = 0;
+                                if (++i12 == ne02) {
+                                    i12 = 0;
+                                    if (++i13 == ne03) {
+                                        i13 = 0;
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+                i10 += ne00 * (ne01 - ir1);
+                while (i10 >= ne0) {
+                    i10 -= ne0;
+                    if (++i11 == ne1) {
+                        i11 = 0;
+                        if (++i12 == ne2) {
+                            i12 = 0;
+                            if (++i13 == ne3) {
+                                i13 = 0;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    } else if (dst->type == GGML_TYPE_F16) {
+        for (int64_t i03 = 0; i03 < ne03; i03++) {
+            for (int64_t i02 = 0; i02 < ne02; i02++) {
+                i10 += ne00 * ir0;
+                while (i10 >= ne0) {
+                    i10 -= ne0;
+                    if (++i11 == ne1) {
+                        i11 = 0;
+                        if (++i12 == ne2) {
+                            i12 = 0;
+                            if (++i13 == ne3) {
+                                i13 = 0;
+                            }
+                        }
+                    }
+                }
+                for (int64_t i01 = ir0; i01 < ir1; i01++) {
+                    for (int64_t i00 = 0; i00 < ne00; i00++) {
+                        const char * src0_ptr = ((char *) src0->data + i00*nb00 + i01*nb01 + i02*nb02 + i03*nb03);
+                              char * dst_ptr  = ((char *)  dst->data + i10*nb0  + i11*nb1  + i12*nb2  + i13*nb3);
+
+                        *(ggml_fp16_t *) dst_ptr = GGML_FP32_TO_FP16(GGML_BF16_TO_FP32(*(const ggml_bf16_t *) src0_ptr));
 
                         if (++i10 == ne0) {
                             i10 = 0;
@@ -7700,7 +8001,7 @@ static void ggml_compute_forward_dup_f32(
                 }
             }
         }
-    } else if (dst->type == GGML_TYPE_F16) {
+    } else if (dst->type == GGML_TYPE_F32) {
         for (int64_t i03 = 0; i03 < ne03; i03++) {
             for (int64_t i02 = 0; i02 < ne02; i02++) {
                 i10 += ne00 * ir0;
@@ -7721,7 +8022,7 @@ static void ggml_compute_forward_dup_f32(
                         const char * src0_ptr = ((char *) src0->data + i00*nb00 + i01*nb01 + i02*nb02 + i03*nb03);
                               char * dst_ptr  = ((char *)  dst->data + i10*nb0  + i11*nb1  + i12*nb2  + i13*nb3);
 
-                        *(ggml_fp16_t *) dst_ptr = GGML_FP32_TO_FP16(*(const float *) src0_ptr);
+                        *(float *) dst_ptr = GGML_BF16_TO_FP32(*(const ggml_bf16_t *) src0_ptr);
 
                         if (++i10 == ne0) {
                             i10 = 0;
@@ -7757,31 +8058,27 @@ static void ggml_compute_forward_dup_f32(
     }
 }
 
-// A simplified version of ggml_compute_forward_dup that doesn't do float upcasting, and just plain old memcpy.
-static void ggml_compute_forward_dup_bytes(
+static void ggml_compute_forward_dup_f32(
         const struct ggml_compute_params * params,
         struct ggml_tensor * dst) {
 
     const struct ggml_tensor * src0 = dst->src[0];
 
     GGML_ASSERT(ggml_nelements(dst) == ggml_nelements(src0));
-    GGML_ASSERT(src0->type == dst->type);
 
     if (params->type == GGML_TASK_TYPE_INIT || params->type == GGML_TASK_TYPE_FINALIZE) {
         return;
     }
 
-    if (ggml_is_contiguous(src0) && ggml_is_contiguous(dst)) {
-        ggml_compute_forward_dup_same_cont(params, dst);
-        return;
-    }
-
-    GGML_TENSOR_UNARY_OP_LOCALS;
+    GGML_TENSOR_UNARY_OP_LOCALS
 
-    const size_t type_size = ggml_type_size(src0->type);
     const int ith = params->ith; // thread index
     const int nth = params->nth; // number of threads
 
+    if (ggml_is_contiguous(src0) && ggml_is_contiguous(dst) && src0->type == dst->type) {
+        ggml_compute_forward_dup_same_cont(params, dst);
+        return;
+    }
 
     // parallelize by rows
     const int nr = ne01;
@@ -7793,9 +8090,9 @@ static void ggml_compute_forward_dup_bytes(
 
     if (src0->type == dst->type &&
         ne00 == ne0 &&
-        nb00 == type_size && nb0 == type_size) {
+        nb00 == ggml_type_size(src0->type) && nb0 == ggml_type_size(dst->type)) {
         // copy by rows
-        const size_t rs = ne00 * type_size;
+        const size_t rs = ne00*nb00;
         for (int64_t i03 = 0; i03 < ne03; i03++) {
             for (int64_t i02 = 0; i02 < ne02; i02++) {
                 for (int64_t i01 = ir0; i01 < ir1; i01++) {
@@ -7810,41 +8107,366 @@ static void ggml_compute_forward_dup_bytes(
     }
 
     if (ggml_is_contiguous(dst)) {
-        size_t id = 0;
-        char * dst_ptr = (char *) dst->data;
-        const size_t rs = ne00 * type_size;
-
-        if (nb00 == type_size) {
-            // src0 is contigous on first dimension, copy by rows
-            for (int64_t i03 = 0; i03 < ne03; i03++) {
-                for (int64_t i02 = 0; i02 < ne02; i02++) {
-                    id += rs * ir0;
-                    for (int64_t i01 = ir0; i01 < ir1; i01++) {
-                        const char * src0_ptr = (char *) src0->data + i01*nb01 + i02*nb02 + i03*nb03;
-                        memcpy(dst_ptr + id, src0_ptr, rs);
-                        id += rs;
-                    }
-                    id += rs * (ne01 - ir1);
-                }
-            }
-        } else {
-            //printf("%s: this is not optimal - fix me\n", __func__);
-
-            for (int64_t i03 = 0; i03 < ne03; i03++) {
-                for (int64_t i02 = 0; i02 < ne02; i02++) {
-                    id += rs * ir0;
-                    for (int64_t i01 = ir0; i01 < ir1; i01++) {
-                        for (int64_t i00 = 0; i00 < ne00; i00++) {
-                            const char * src0_ptr = (char *) src0->data + i00*nb00 + i01*nb01 + i02*nb02 + i03*nb03;
-                            memcpy(dst_ptr + id, src0_ptr, type_size);
+        // TODO: simplify
+        if (nb00 == sizeof(float)) {
+            if (dst->type == GGML_TYPE_F32) {
+                size_t id = 0;
+                const size_t rs = ne00 * nb00;
+                char * dst_ptr = (char *) dst->data;
 
-                            id += type_size;
+                for (int i03 = 0; i03 < ne03; i03++) {
+                    for (int i02 = 0; i02 < ne02; i02++) {
+                        id += rs * ir0;
+                        for (int i01 = ir0; i01 < ir1; i01++) {
+                            const char * src0_ptr = (char *) src0->data + i01*nb01 + i02*nb02 + i03*nb03;
+                            memcpy(dst_ptr + id, src0_ptr, rs);
+                            id += rs;
                         }
+                        id += rs * (ne01 - ir1);
                     }
-                    id += rs * (ne01 - ir1);
                 }
-            }
-        }
+            } else if (type_traits[dst->type].from_float) {
+                ggml_from_float_t const quantize_row_q = type_traits[dst->type].from_float;
+
+                size_t id = 0;
+                size_t rs = nb0 * (ne00 / ggml_blck_size(dst->type));
+                char * dst_ptr = (char *) dst->data;
+
+                for (int i03 = 0; i03 < ne03; i03++) {
+                    for (int i02 = 0; i02 < ne02; i02++) {
+                        id += rs * ir0;
+                        for (int i01 = ir0; i01 < ir1; i01++) {
+                            const float * src0_ptr = (float *) ((char *) src0->data + i01*nb01 + i02*nb02 + i03*nb03);
+                            quantize_row_q(src0_ptr, dst_ptr + id, ne00);
+                            id += rs;
+                        }
+                        id += rs * (ne01 - ir1);
+                    }
+                }
+            } else {
+                GGML_ASSERT(false); // TODO: implement
+            }
+        } else {
+            //printf("%s: this is not optimal - fix me\n", __func__);
+
+            if (dst->type == GGML_TYPE_F32) {
+                size_t id = 0;
+                float * dst_ptr = (float *) dst->data;
+
+                for (int i03 = 0; i03 < ne03; i03++) {
+                    for (int i02 = 0; i02 < ne02; i02++) {
+                        id += ne00 * ir0;
+                        for (int i01 = ir0; i01 < ir1; i01++) {
+                            for (int i00 = 0; i00 < ne00; i00++) {
+                                const float * src0_ptr = (float *) ((char *) src0->data + i00*nb00 + i01*nb01 + i02*nb02 + i03*nb03);
+
+                                dst_ptr[id] = *src0_ptr;
+                                id++;
+                            }
+                        }
+                        id += ne00 * (ne01 - ir1);
+                    }
+                }
+            } else if (dst->type == GGML_TYPE_F16) {
+                size_t id = 0;
+                ggml_fp16_t * dst_ptr = (ggml_fp16_t *) dst->data;
+
+                for (int i03 = 0; i03 < ne03; i03++) {
+                    for (int i02 = 0; i02 < ne02; i02++) {
+                        id += ne00 * ir0;
+                        for (int i01 = ir0; i01 < ir1; i01++) {
+                            for (int i00 = 0; i00 < ne00; i00++) {
+                                const float * src0_ptr = (float *) ((char *) src0->data + i00*nb00 + i01*nb01 + i02*nb02 + i03*nb03);
+
+                                dst_ptr[id] = GGML_FP32_TO_FP16(*src0_ptr);
+                                id++;
+                            }
+                        }
+                        id += ne00 * (ne01 - ir1);
+                    }
+                }
+            } else if (dst->type == GGML_TYPE_BF16) {
+                size_t id = 0;
+                ggml_bf16_t * dst_ptr = (ggml_bf16_t *) dst->data;
+
+                for (int i03 = 0; i03 < ne03; i03++) {
+                    for (int i02 = 0; i02 < ne02; i02++) {
+                        id += ne00 * ir0;
+                        for (int i01 = ir0; i01 < ir1; i01++) {
+                            for (int i00 = 0; i00 < ne00; i00++) {
+                                const float * src0_ptr = (float *) ((char *) src0->data + i00*nb00 + i01*nb01 + i02*nb02 + i03*nb03);
+
+                                dst_ptr[id] = GGML_FP32_TO_BF16(*src0_ptr);
+                                id++;
+                            }
+                        }
+                        id += ne00 * (ne01 - ir1);
+                    }
+                }
+            } else {
+                GGML_ASSERT(false); // TODO: implement
+            }
+        }
+
+        return;
+    }
+
+    // dst counters
+
+    int64_t i10 = 0;
+    int64_t i11 = 0;
+    int64_t i12 = 0;
+    int64_t i13 = 0;
+
+    if (dst->type == GGML_TYPE_F32) {
+        for (int64_t i03 = 0; i03 < ne03; i03++) {
+            for (int64_t i02 = 0; i02 < ne02; i02++) {
+                i10 += ne00 * ir0;
+                while (i10 >= ne0) {
+                    i10 -= ne0;
+                    if (++i11 == ne1) {
+                        i11 = 0;
+                        if (++i12 == ne2) {
+                            i12 = 0;
+                            if (++i13 == ne3) {
+                                i13 = 0;
+                            }
+                        }
+                    }
+                }
+                for (int64_t i01 = ir0; i01 < ir1; i01++) {
+                    for (int64_t i00 = 0; i00 < ne00; i00++) {
+                        const char * src0_ptr = ((char *) src0->data + i00*nb00 + i01*nb01 + i02*nb02 + i03*nb03);
+                              char * dst_ptr  = ((char *)  dst->data + i10*nb0  + i11*nb1  + i12*nb2  + i13*nb3);
+
+                        memcpy(dst_ptr, src0_ptr, sizeof(float));
+
+                        if (++i10 == ne0) {
+                            i10 = 0;
+                            if (++i11 == ne1) {
+                                i11 = 0;
+                                if (++i12 == ne2) {
+                                    i12 = 0;
+                                    if (++i13 == ne3) {
+                                        i13 = 0;
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+                i10 += ne00 * (ne01 - ir1);
+                while (i10 >= ne0) {
+                    i10 -= ne0;
+                    if (++i11 == ne1) {
+                        i11 = 0;
+                        if (++i12 == ne2) {
+                            i12 = 0;
+                            if (++i13 == ne3) {
+                                i13 = 0;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    } else if (dst->type == GGML_TYPE_F16) {
+        for (int64_t i03 = 0; i03 < ne03; i03++) {
+            for (int64_t i02 = 0; i02 < ne02; i02++) {
+                i10 += ne00 * ir0;
+                while (i10 >= ne0) {
+                    i10 -= ne0;
+                    if (++i11 == ne1) {
+                        i11 = 0;
+                        if (++i12 == ne2) {
+                            i12 = 0;
+                            if (++i13 == ne3) {
+                                i13 = 0;
+                            }
+                        }
+                    }
+                }
+                for (int64_t i01 = ir0; i01 < ir1; i01++) {
+                    for (int64_t i00 = 0; i00 < ne00; i00++) {
+                        const char * src0_ptr = ((char *) src0->data + i00*nb00 + i01*nb01 + i02*nb02 + i03*nb03);
+                              char * dst_ptr  = ((char *)  dst->data + i10*nb0  + i11*nb1  + i12*nb2  + i13*nb3);
+
+                        *(ggml_fp16_t *) dst_ptr = GGML_FP32_TO_FP16(*(const float *) src0_ptr);
+
+                        if (++i10 == ne0) {
+                            i10 = 0;
+                            if (++i11 == ne1) {
+                                i11 = 0;
+                                if (++i12 == ne2) {
+                                    i12 = 0;
+                                    if (++i13 == ne3) {
+                                        i13 = 0;
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+                i10 += ne00 * (ne01 - ir1);
+                while (i10 >= ne0) {
+                    i10 -= ne0;
+                    if (++i11 == ne1) {
+                        i11 = 0;
+                        if (++i12 == ne2) {
+                            i12 = 0;
+                            if (++i13 == ne3) {
+                                i13 = 0;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    } else if (dst->type == GGML_TYPE_BF16) {
+        for (int64_t i03 = 0; i03 < ne03; i03++) {
+            for (int64_t i02 = 0; i02 < ne02; i02++) {
+                i10 += ne00 * ir0;
+                while (i10 >= ne0) {
+                    i10 -= ne0;
+                    if (++i11 == ne1) {
+                        i11 = 0;
+                        if (++i12 == ne2) {
+                            i12 = 0;
+                            if (++i13 == ne3) {
+                                i13 = 0;
+                            }
+                        }
+                    }
+                }
+                for (int64_t i01 = ir0; i01 < ir1; i01++) {
+                    for (int64_t i00 = 0; i00 < ne00; i00++) {
+                        const char * src0_ptr = ((char *) src0->data + i00*nb00 + i01*nb01 + i02*nb02 + i03*nb03);
+                              char * dst_ptr  = ((char *)  dst->data + i10*nb0  + i11*nb1  + i12*nb2  + i13*nb3);
+
+                        *(ggml_bf16_t *) dst_ptr = GGML_FP32_TO_BF16(*(const float *) src0_ptr);
+
+                        if (++i10 == ne0) {
+                            i10 = 0;
+                            if (++i11 == ne1) {
+                                i11 = 0;
+                                if (++i12 == ne2) {
+                                    i12 = 0;
+                                    if (++i13 == ne3) {
+                                        i13 = 0;
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+                i10 += ne00 * (ne01 - ir1);
+                while (i10 >= ne0) {
+                    i10 -= ne0;
+                    if (++i11 == ne1) {
+                        i11 = 0;
+                        if (++i12 == ne2) {
+                            i12 = 0;
+                            if (++i13 == ne3) {
+                                i13 = 0;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    } else {
+        GGML_ASSERT(false); // TODO: implement
+    }
+}
+
+// A simplified version of ggml_compute_forward_dup that doesn't do float upcasting, and just plain old memcpy.
+static void ggml_compute_forward_dup_bytes(
+        const struct ggml_compute_params * params,
+        struct ggml_tensor * dst) {
+
+    const struct ggml_tensor * src0 = dst->src[0];
+
+    GGML_ASSERT(ggml_nelements(dst) == ggml_nelements(src0));
+    GGML_ASSERT(src0->type == dst->type);
+
+    if (params->type == GGML_TASK_TYPE_INIT || params->type == GGML_TASK_TYPE_FINALIZE) {
+        return;
+    }
+
+    if (ggml_is_contiguous(src0) && ggml_is_contiguous(dst)) {
+        ggml_compute_forward_dup_same_cont(params, dst);
+        return;
+    }
+
+    GGML_TENSOR_UNARY_OP_LOCALS;
+
+    const size_t type_size = ggml_type_size(src0->type);
+    const int ith = params->ith; // thread index
+    const int nth = params->nth; // number of threads
+
+
+    // parallelize by rows
+    const int nr = ne01;
+    // number of rows per thread
+    const int dr = (nr + nth - 1) / nth;
+    // row range for this thread
+    const int ir0 = dr * ith;
+    const int ir1 = MIN(ir0 + dr, nr);
+
+    if (src0->type == dst->type &&
+        ne00 == ne0 &&
+        nb00 == type_size && nb0 == type_size) {
+        // copy by rows
+        const size_t rs = ne00 * type_size;
+        for (int64_t i03 = 0; i03 < ne03; i03++) {
+            for (int64_t i02 = 0; i02 < ne02; i02++) {
+                for (int64_t i01 = ir0; i01 < ir1; i01++) {
+                    memcpy(
+                        ((char *)  dst->data + i01*nb1  + i02*nb2  + i03*nb3),
+                        ((char *) src0->data + i01*nb01 + i02*nb02 + i03*nb03),
+                        rs);
+                }
+            }
+        }
+        return;
+    }
+
+    if (ggml_is_contiguous(dst)) {
+        size_t id = 0;
+        char * dst_ptr = (char *) dst->data;
+        const size_t rs = ne00 * type_size;
+
+        if (nb00 == type_size) {
+            // src0 is contigous on first dimension, copy by rows
+            for (int64_t i03 = 0; i03 < ne03; i03++) {
+                for (int64_t i02 = 0; i02 < ne02; i02++) {
+                    id += rs * ir0;
+                    for (int64_t i01 = ir0; i01 < ir1; i01++) {
+                        const char * src0_ptr = (char *) src0->data + i01*nb01 + i02*nb02 + i03*nb03;
+                        memcpy(dst_ptr + id, src0_ptr, rs);
+                        id += rs;
+                    }
+                    id += rs * (ne01 - ir1);
+                }
+            }
+        } else {
+            //printf("%s: this is not optimal - fix me\n", __func__);
+
+            for (int64_t i03 = 0; i03 < ne03; i03++) {
+                for (int64_t i02 = 0; i02 < ne02; i02++) {
+                    id += rs * ir0;
+                    for (int64_t i01 = ir0; i01 < ir1; i01++) {
+                        for (int64_t i00 = 0; i00 < ne00; i00++) {
+                            const char * src0_ptr = (char *) src0->data + i00*nb00 + i01*nb01 + i02*nb02 + i03*nb03;
+                            memcpy(dst_ptr + id, src0_ptr, type_size);
+
+                            id += type_size;
+                        }
+                    }
+                    id += rs * (ne01 - ir1);
+                }
+            }
+        }
 
         return;
     }
@@ -7925,6 +8547,10 @@ static void ggml_compute_forward_dup(
             {
                 ggml_compute_forward_dup_f16(params, dst);
             } break;
+        case GGML_TYPE_BF16:
+            {
+                ggml_compute_forward_dup_bf16(params, dst);
+            } break;
         case GGML_TYPE_F32:
             {
                 ggml_compute_forward_dup_f32(params, dst);
@@ -8018,17 +8644,96 @@ static void ggml_compute_forward_add_f32(
             float * dst_ptr  = (float *) ((char *) dst->data  + i03*nb3  + i02*nb2  + i01*nb1 );
             float * src0_ptr = (float *) ((char *) src0->data + i03*nb03 + i02*nb02 + i01*nb01);
 
-            for (int64_t i0 = 0; i0 < ne0; ++i0) {
-                const int64_t i10 = i0 % ne10;
-                float * src1_ptr = (float *) ((char *) src1->data + i13*nb13 + i12*nb12 + i11*nb11 + i10*nb10);
+            for (int64_t i0 = 0; i0 < ne0; ++i0) {
+                const int64_t i10 = i0 % ne10;
+                float * src1_ptr = (float *) ((char *) src1->data + i13*nb13 + i12*nb12 + i11*nb11 + i10*nb10);
+
+                dst_ptr[i0] = src0_ptr[i0] + *src1_ptr;
+            }
+        }
+    }
+}
+
+static void ggml_compute_forward_add_f16_f32(
+        const struct ggml_compute_params * params,
+        struct ggml_tensor * dst) {
+
+    const struct ggml_tensor * src0 = dst->src[0];
+    const struct ggml_tensor * src1 = dst->src[1];
+
+    GGML_ASSERT(ggml_are_same_shape(src0, src1) && ggml_are_same_shape(src0, dst));
+
+    if (params->type == GGML_TASK_TYPE_INIT || params->type == GGML_TASK_TYPE_FINALIZE) {
+        return;
+    }
+
+    const int ith = params->ith;
+    const int nth = params->nth;
+
+    const int nr  = ggml_nrows(src0);
+
+    GGML_TENSOR_BINARY_OP_LOCALS
+
+    GGML_ASSERT(src0->type == GGML_TYPE_F16);
+    GGML_ASSERT(src1->type == GGML_TYPE_F32);
+
+    if (dst->type == GGML_TYPE_F32) {
+        GGML_ASSERT( nb0 == sizeof(float));
+    }
+    else {
+        GGML_ASSERT(dst->type  == GGML_TYPE_F16);
+        GGML_ASSERT( nb0 == sizeof(ggml_fp16_t));
+    }
+
+    GGML_ASSERT(nb00 == sizeof(ggml_fp16_t));
+
+    // rows per thread
+    const int dr = (nr + nth - 1)/nth;
+
+    // row range for this thread
+    const int ir0 = dr*ith;
+    const int ir1 = MIN(ir0 + dr, nr);
+
+    if (nb10 == sizeof(float)) {
+        if (dst->type == GGML_TYPE_F16) {
+            for (int ir = ir0; ir < ir1; ++ir) {
+                // src0, src1 and dst are same shape => same indices
+                const int i3 = ir/(ne2*ne1);
+                const int i2 = (ir - i3*ne2*ne1)/ne1;
+                const int i1 = (ir - i3*ne2*ne1 - i2*ne1);
+
+                ggml_fp16_t * dst_ptr  = (ggml_fp16_t *) ((char *) dst->data  + i3*nb3  + i2*nb2  + i1*nb1);
+                ggml_fp16_t * src0_ptr = (ggml_fp16_t *) ((char *) src0->data + i3*nb03 + i2*nb02 + i1*nb01);
+                float *       src1_ptr = (float *)       ((char *) src1->data + i3*nb13 + i2*nb12 + i1*nb11);
+
+                for (int i = 0; i < ne0; i++) {
+                    dst_ptr[i] = GGML_FP32_TO_FP16(GGML_FP16_TO_FP32(src0_ptr[i]) + src1_ptr[i]);
+                }
+            }
+        } else {
+            for (int ir = ir0; ir < ir1; ++ir) {
+                // src0, src1 and dst are same shape => same indices
+                const int i3 = ir/(ne2*ne1);
+                const int i2 = (ir - i3*ne2*ne1)/ne1;
+                const int i1 = (ir - i3*ne2*ne1 - i2*ne1);
+
+                float *       dst_ptr  = (float *)       ((char *) dst->data  + i3*nb3  + i2*nb2  + i1*nb1);
+                ggml_fp16_t * src0_ptr = (ggml_fp16_t *) ((char *) src0->data + i3*nb03 + i2*nb02 + i1*nb01);
+                float *       src1_ptr = (float *)       ((char *) src1->data + i3*nb13 + i2*nb12 + i1*nb11);
 
-                dst_ptr[i0] = src0_ptr[i0] + *src1_ptr;
+                for (int i = 0; i < ne0; i++) {
+                    dst_ptr[i] = GGML_FP16_TO_FP32(src0_ptr[i]) + src1_ptr[i];
+                }
             }
         }
     }
+    else {
+        // src1 is not contiguous
+        GGML_ASSERT(false);
+    }
 }
 
-static void ggml_compute_forward_add_f16_f32(
+static void ggml_compute_forward_add_bf16_f32(
         const struct ggml_compute_params * params,
         struct ggml_tensor * dst) {
 
@@ -8048,18 +8753,18 @@ static void ggml_compute_forward_add_f16_f32(
 
     GGML_TENSOR_BINARY_OP_LOCALS
 
-    GGML_ASSERT(src0->type == GGML_TYPE_F16);
+    GGML_ASSERT(src0->type == GGML_TYPE_BF16);
     GGML_ASSERT(src1->type == GGML_TYPE_F32);
 
     if (dst->type == GGML_TYPE_F32) {
         GGML_ASSERT( nb0 == sizeof(float));
     }
     else {
-        GGML_ASSERT(dst->type  == GGML_TYPE_F16);
-        GGML_ASSERT( nb0 == sizeof(ggml_fp16_t));
+        GGML_ASSERT(dst->type  == GGML_TYPE_BF16);
+        GGML_ASSERT( nb0 == sizeof(ggml_bf16_t));
     }
 
-    GGML_ASSERT(nb00 == sizeof(ggml_fp16_t));
+    GGML_ASSERT(nb00 == sizeof(ggml_bf16_t));
 
     // rows per thread
     const int dr = (nr + nth - 1)/nth;
@@ -8069,19 +8774,19 @@ static void ggml_compute_forward_add_f16_f32(
     const int ir1 = MIN(ir0 + dr, nr);
 
     if (nb10 == sizeof(float)) {
-        if (dst->type == GGML_TYPE_F16) {
+        if (dst->type == GGML_TYPE_BF16) {
             for (int ir = ir0; ir < ir1; ++ir) {
                 // src0, src1 and dst are same shape => same indices
                 const int i3 = ir/(ne2*ne1);
                 const int i2 = (ir - i3*ne2*ne1)/ne1;
                 const int i1 = (ir - i3*ne2*ne1 - i2*ne1);
 
-                ggml_fp16_t * dst_ptr  = (ggml_fp16_t *) ((char *) dst->data  + i3*nb3  + i2*nb2  + i1*nb1);
-                ggml_fp16_t * src0_ptr = (ggml_fp16_t *) ((char *) src0->data + i3*nb03 + i2*nb02 + i1*nb01);
+                ggml_bf16_t * dst_ptr  = (ggml_bf16_t *) ((char *) dst->data  + i3*nb3  + i2*nb2  + i1*nb1);
+                ggml_bf16_t * src0_ptr = (ggml_bf16_t *) ((char *) src0->data + i3*nb03 + i2*nb02 + i1*nb01);
                 float *       src1_ptr = (float *)       ((char *) src1->data + i3*nb13 + i2*nb12 + i1*nb11);
 
                 for (int i = 0; i < ne0; i++) {
-                    dst_ptr[i] = GGML_FP32_TO_FP16(GGML_FP16_TO_FP32(src0_ptr[i]) + src1_ptr[i]);
+                    dst_ptr[i] = GGML_FP32_TO_BF16(GGML_BF16_TO_FP32(src0_ptr[i]) + src1_ptr[i]);
                 }
             }
         } else {
@@ -8092,11 +8797,11 @@ static void ggml_compute_forward_add_f16_f32(
                 const int i1 = (ir - i3*ne2*ne1 - i2*ne1);
 
                 float *       dst_ptr  = (float *)       ((char *) dst->data  + i3*nb3  + i2*nb2  + i1*nb1);
-                ggml_fp16_t * src0_ptr = (ggml_fp16_t *) ((char *) src0->data + i3*nb03 + i2*nb02 + i1*nb01);
+                ggml_bf16_t * src0_ptr = (ggml_bf16_t *) ((char *) src0->data + i3*nb03 + i2*nb02 + i1*nb01);
                 float *       src1_ptr = (float *)       ((char *) src1->data + i3*nb13 + i2*nb12 + i1*nb11);
 
                 for (int i = 0; i < ne0; i++) {
-                    dst_ptr[i] = GGML_FP16_TO_FP32(src0_ptr[i]) + src1_ptr[i];
+                    dst_ptr[i] = GGML_BF16_TO_FP32(src0_ptr[i]) + src1_ptr[i];
                 }
             }
         }
@@ -8163,6 +8868,62 @@ static void ggml_compute_forward_add_f16_f16(
     }
 }
 
+static void ggml_compute_forward_add_bf16_bf16(
+        const struct ggml_compute_params * params,
+        struct ggml_tensor * dst) {
+
+    const struct ggml_tensor * src0 = dst->src[0];
+    const struct ggml_tensor * src1 = dst->src[1];
+
+    GGML_ASSERT(ggml_are_same_shape(src0, src1) && ggml_are_same_shape(src0, dst));
+
+    if (params->type == GGML_TASK_TYPE_INIT || params->type == GGML_TASK_TYPE_FINALIZE) {
+        return;
+    }
+
+    const int ith = params->ith;
+    const int nth = params->nth;
+
+    const int nr  = ggml_nrows(src0);
+
+    GGML_TENSOR_BINARY_OP_LOCALS
+
+    GGML_ASSERT(src0->type == GGML_TYPE_BF16);
+    GGML_ASSERT(src1->type == GGML_TYPE_BF16);
+    GGML_ASSERT(dst->type  == GGML_TYPE_BF16);
+
+    GGML_ASSERT( nb0 == sizeof(ggml_bf16_t));
+    GGML_ASSERT(nb00 == sizeof(ggml_bf16_t));
+
+    // rows per thread
+    const int dr = (nr + nth - 1)/nth;
+
+    // row range for this thread
+    const int ir0 = dr*ith;
+    const int ir1 = MIN(ir0 + dr, nr);
+
+    if (nb10 == sizeof(ggml_bf16_t)) {
+        for (int ir = ir0; ir < ir1; ++ir) {
+            // src0, src1 and dst are same shape => same indices
+            const int i3 = ir/(ne2*ne1);
+            const int i2 = (ir - i3*ne2*ne1)/ne1;
+            const int i1 = (ir - i3*ne2*ne1 - i2*ne1);
+
+            ggml_bf16_t * dst_ptr  = (ggml_bf16_t *) ((char *) dst->data  + i3*nb3  + i2*nb2  + i1*nb1);
+            ggml_bf16_t * src0_ptr = (ggml_bf16_t *) ((char *) src0->data + i3*nb03 + i2*nb02 + i1*nb01);
+            ggml_bf16_t * src1_ptr = (ggml_bf16_t *) ((char *) src1->data + i3*nb13 + i2*nb12 + i1*nb11);
+
+            for (int i = 0; i < ne0; i++) {
+                dst_ptr[i] = GGML_FP32_TO_BF16(GGML_BF16_TO_FP32(src0_ptr[i]) + GGML_BF16_TO_FP32(src1_ptr[i]));
+            }
+        }
+    }
+    else {
+        // src1 is not contiguous
+        GGML_ASSERT(false);
+    }
+}
+
 static void ggml_compute_forward_add_q_f32(
         const struct ggml_compute_params * params,
         struct ggml_tensor * dst) {
@@ -8272,6 +9033,18 @@ static void ggml_compute_forward_add(
                     GGML_ASSERT(false);
                 }
             } break;
+        case GGML_TYPE_BF16:
+            {
+                if (src1->type == GGML_TYPE_BF16) {
+                    ggml_compute_forward_add_bf16_bf16(params, dst);
+                }
+                else if (src1->type == GGML_TYPE_F32) {
+                    ggml_compute_forward_add_bf16_f32(params, dst);
+                }
+                else {
+                    GGML_ASSERT(false);
+                }
+            } break;
         case GGML_TYPE_Q4_0:
         case GGML_TYPE_Q4_1:
         case GGML_TYPE_Q5_0:
@@ -8530,6 +9303,110 @@ static void ggml_compute_forward_add1_q_f32(
     }
 }
 
+static void ggml_compute_forward_add1_bf16_f32(
+        const struct ggml_compute_params * params,
+        struct ggml_tensor * dst) {
+
+    const struct ggml_tensor * src0 = dst->src[0];
+    const struct ggml_tensor * src1 = dst->src[1];
+
+    GGML_ASSERT(ggml_are_same_shape(src0, dst));
+    GGML_ASSERT(ggml_is_scalar(src1));
+
+    if (params->type == GGML_TASK_TYPE_INIT || params->type == GGML_TASK_TYPE_FINALIZE) {
+        return;
+    }
+
+    // scalar to add
+    const float v = *(float *) src1->data;
+
+    const int ith = params->ith;
+    const int nth = params->nth;
+
+    const int nr  = ggml_nrows(src0);
+
+    GGML_TENSOR_UNARY_OP_LOCALS
+
+    GGML_ASSERT(src0->type == GGML_TYPE_BF16);
+    GGML_ASSERT(src1->type == GGML_TYPE_F32);
+    GGML_ASSERT(dst->type  == GGML_TYPE_BF16);
+
+    GGML_ASSERT( nb0 == sizeof(ggml_bf16_t));
+    GGML_ASSERT(nb00 == sizeof(ggml_bf16_t));
+
+    // rows per thread
+    const int dr = (nr + nth - 1)/nth;
+
+    // row range for this thread
+    const int ir0 = dr*ith;
+    const int ir1 = MIN(ir0 + dr, nr);
+
+    for (int ir = ir0; ir < ir1; ++ir) {
+        // src0 and dst are same shape => same indices
+        const int i3 = ir/(ne2*ne1);
+        const int i2 = (ir - i3*ne2*ne1)/ne1;
+        const int i1 = (ir - i3*ne2*ne1 - i2*ne1);
+
+        ggml_bf16_t * dst_ptr  = (ggml_bf16_t *) ((char *) dst->data  + i3*nb3  + i2*nb2  + i1*nb1 );
+        ggml_bf16_t * src0_ptr = (ggml_bf16_t *) ((char *) src0->data + i3*nb03 + i2*nb02 + i1*nb01);
+        for (int i = 0; i < ne0; i++) {
+            dst_ptr[i] = GGML_FP32_TO_BF16(GGML_BF16_TO_FP32(src0_ptr[i]) + v);
+        }
+    }
+}
+
+static void ggml_compute_forward_add1_bf16_bf16(
+        const struct ggml_compute_params * params,
+        struct ggml_tensor * dst) {
+
+    const struct ggml_tensor * src0 = dst->src[0];
+    const struct ggml_tensor * src1 = dst->src[1];
+
+    GGML_ASSERT(ggml_are_same_shape(src0, dst));
+    GGML_ASSERT(ggml_is_scalar(src1));
+
+    if (params->type == GGML_TASK_TYPE_INIT || params->type == GGML_TASK_TYPE_FINALIZE) {
+        return;
+    }
+
+    // scalar to add
+    const float v = GGML_BF16_TO_FP32(*(ggml_bf16_t *) src1->data);
+
+    const int ith = params->ith;
+    const int nth = params->nth;
+
+    const int nr  = ggml_nrows(src0);
+
+    GGML_TENSOR_UNARY_OP_LOCALS
+
+    GGML_ASSERT(src0->type == GGML_TYPE_BF16);
+    GGML_ASSERT(src1->type == GGML_TYPE_BF16);
+    GGML_ASSERT(dst->type  == GGML_TYPE_BF16);
+
+    GGML_ASSERT( nb0 == sizeof(ggml_bf16_t));
+    GGML_ASSERT(nb00 == sizeof(ggml_bf16_t));
+
+    // rows per thread
+    const int dr = (nr + nth - 1)/nth;
+
+    // row range for this thread
+    const int ir0 = dr*ith;
+    const int ir1 = MIN(ir0 + dr, nr);
+
+    for (int ir = ir0; ir < ir1; ++ir) {
+        // src0 and dst are same shape => same indices
+        const int i3 = ir/(ne2*ne1);
+        const int i2 = (ir - i3*ne2*ne1)/ne1;
+        const int i1 = (ir - i3*ne2*ne1 - i2*ne1);
+
+        ggml_bf16_t * dst_ptr  = (ggml_bf16_t *) ((char *) dst->data  + i3*nb3  + i2*nb2  + i1*nb1 );
+        ggml_bf16_t * src0_ptr = (ggml_bf16_t *) ((char *) src0->data + i3*nb03 + i2*nb02 + i1*nb01);
+        for (int i = 0; i < ne0; i++) {
+            dst_ptr[i] = GGML_FP32_TO_BF16(GGML_BF16_TO_FP32(src0_ptr[i]) + v);
+        }
+    }
+}
+
 static void ggml_compute_forward_add1(
         const struct ggml_compute_params * params,
         struct ggml_tensor * dst) {
@@ -8554,6 +9431,18 @@ static void ggml_compute_forward_add1(
                     GGML_ASSERT(false);
                 }
             } break;
+        case GGML_TYPE_BF16:
+            {
+                if (src1->type == GGML_TYPE_BF16) {
+                    ggml_compute_forward_add1_bf16_bf16(params, dst);
+                }
+                else if (src1->type == GGML_TYPE_F32) {
+                    ggml_compute_forward_add1_bf16_f32(params, dst);
+                }
+                else {
+                    GGML_ASSERT(false);
+                }
+            } break;
         case GGML_TYPE_Q4_0:
         case GGML_TYPE_Q4_1:
         case GGML_TYPE_Q5_0:
@@ -8682,6 +9571,7 @@ static void ggml_compute_forward_acc(
                 ggml_compute_forward_acc_f32(params, dst);
             } break;
         case GGML_TYPE_F16:
+        case GGML_TYPE_BF16:
         case GGML_TYPE_Q4_0:
         case GGML_TYPE_Q4_1:
         case GGML_TYPE_Q5_0:
@@ -9203,6 +10093,40 @@ static void ggml_compute_forward_sum_f16(
     ((ggml_fp16_t *) dst->data)[0] = GGML_FP32_TO_FP16(sum);
 }
 
+static void ggml_compute_forward_sum_bf16(
+    const struct ggml_compute_params * params,
+          struct ggml_tensor * dst) {
+
+    const struct ggml_tensor * src0 = dst->src[0];
+
+    assert(params->ith == 0);
+    assert(ggml_is_scalar(dst));
+
+    if (params->type == GGML_TASK_TYPE_INIT || params->type == GGML_TASK_TYPE_FINALIZE) {
+        return;
+    }
+
+    assert(src0->nb[0] == sizeof(ggml_bf16_t));
+
+    GGML_TENSOR_LOCALS(int64_t, ne0, src0, ne)
+    GGML_TENSOR_LOCALS(size_t,  nb0, src0, nb)
+
+    float sum = 0;
+    float row_sum = 0;
+
+    for (int64_t i03 = 0; i03 < ne03; i03++) {
+        for (int64_t i02 = 0; i02 < ne02; i02++) {
+            for (int64_t i01 = 0; i01 < ne01; i01++) {
+                ggml_vec_sum_bf16_ggf(ne00,
+                    &row_sum,
+                    (ggml_bf16_t *) ((char *) src0->data + i01 * nb01 + i02 * nb02 + i03 * nb03));
+                sum += row_sum;
+            }
+        }
+    }
+    ((ggml_bf16_t *) dst->data)[0] = GGML_FP32_TO_BF16(sum);
+}
+
 static void ggml_compute_forward_sum(
         const struct ggml_compute_params * params,
         struct ggml_tensor * dst) {
@@ -9218,6 +10142,10 @@ static void ggml_compute_forward_sum(
             {
                 ggml_compute_forward_sum_f16(params, dst);
             } break;
+        case GGML_TYPE_BF16:
+            {
+                ggml_compute_forward_sum_bf16(params, dst);
+            } break;
         default:
             {
                 GGML_ASSERT(false);
@@ -9492,6 +10420,7 @@ static void ggml_compute_forward_repeat(
 
     switch (src0->type) {
         case GGML_TYPE_F16:
+        case GGML_TYPE_BF16:
         case GGML_TYPE_I16:
             {
                 ggml_compute_forward_repeat_f16(params, dst);
@@ -11855,6 +12784,7 @@ static void ggml_compute_forward_set(
                 ggml_compute_forward_set_f32(params, dst);
             } break;
         case GGML_TYPE_F16:
+        case GGML_TYPE_BF16:
         case GGML_TYPE_Q4_0:
         case GGML_TYPE_Q4_1:
         case GGML_TYPE_Q5_0:
@@ -12029,6 +12959,49 @@ static void ggml_compute_forward_get_rows_f16(
     }
 }
 
+static void ggml_compute_forward_get_rows_bf16(
+        const struct ggml_compute_params * params,
+              struct ggml_tensor * dst) {
+
+    const struct ggml_tensor * src0 = dst->src[0];
+    const struct ggml_tensor * src1 = dst->src[1];
+
+    if (params->type == GGML_TASK_TYPE_INIT || params->type == GGML_TASK_TYPE_FINALIZE) {
+        return;
+    }
+
+    GGML_TENSOR_BINARY_OP_LOCALS
+
+    const int64_t nc = ne00;
+    const int64_t nr = ggml_nelements(src1);
+
+    assert(ne0  == nc);
+    assert(ne02 == ne11);
+    assert(nb00 == sizeof(ggml_bf16_t));
+    assert(ggml_nrows(dst) == nr);
+
+    const int ith = params->ith;
+    const int nth = params->nth;
+
+    // rows per thread
+    const int dr = (nr + nth - 1)/nth;
+
+    // row range for this thread
+    const int ir0 = dr*ith;
+    const int ir1 = MIN(ir0 + dr, nr);
+
+    for (int64_t i = ir0; i < ir1; ++i) {
+        const int64_t i12 = i/(ne11*ne10);
+        const int64_t i11 = (i - i12*ne11*ne10)/ne10;
+        const int64_t i10 = (i - i12*ne11*ne10 - i11*ne10);
+        const int64_t i01 = *(int32_t *) ((char *) src1->data + i10*nb10 + i11*nb11 + i12*nb12);
+
+       ggml_bf16_to_fp32_row(
+                (const void *) ((char *) src0->data + i01*nb01 + i11*nb02 + i12*nb03),
+                     (float *) ((char *)  dst->data + i10*nb1  + i11*nb2  + i12*nb3), nc);
+    }
+}
+
 static void ggml_compute_forward_get_rows_f32(
         const struct ggml_compute_params * params,
               struct ggml_tensor * dst) {
@@ -12106,6 +13079,10 @@ static void ggml_compute_forward_get_rows(
             {
                 ggml_compute_forward_get_rows_f16(params, dst);
             } break;
+        case GGML_TYPE_BF16:
+            {
+                ggml_compute_forward_get_rows_bf16(params, dst);
+            } break;
         case GGML_TYPE_F32:
         case GGML_TYPE_I32:
             {
@@ -12801,6 +13778,7 @@ static void ggml_compute_forward_alibi(
             {
                 ggml_compute_forward_alibi_f32(params, dst);
             } break;
+        case GGML_TYPE_BF16:
         case GGML_TYPE_Q4_0:
         case GGML_TYPE_Q4_1:
         case GGML_TYPE_Q5_0:
@@ -12890,6 +13868,7 @@ static void ggml_compute_forward_clamp(
                 ggml_compute_forward_clamp_f32(params, dst);
             } break;
         case GGML_TYPE_F16:
+        case GGML_TYPE_BF16:
         case GGML_TYPE_Q4_0:
         case GGML_TYPE_Q4_1:
         case GGML_TYPE_Q5_0:
@@ -15987,6 +16966,7 @@ static void ggml_compute_forward_get_rel_pos(
 
     switch (src0->type) {
         case GGML_TYPE_F16:
+        case GGML_TYPE_BF16:
             {
                 ggml_compute_forward_get_rel_pos_f16(params, dst);
             } break;
@@ -18856,7 +19836,10 @@ struct ggml_cplan ggml_graph_plan(const struct ggml_cgraph * cgraph, int n_threa
             case GGML_OP_CPY:
             case GGML_OP_DUP:
                 {
-                    if (ggml_is_quantized(node->type)) {
+                    if (ggml_is_quantized(node->type) ||
+                        // F16 -> BF16 and BF16 -> F16 copies go through intermediate F32
+                        (node->src[0]->type == GGML_TYPE_F16  && node->src[1] && node->src[1]->type == GGML_TYPE_BF16) ||
+                        (node->src[0]->type == GGML_TYPE_BF16 && node->src[1] && node->src[1]->type == GGML_TYPE_F16)) {
                         cur = ggml_type_size(GGML_TYPE_F32) * node->ne[0] * n_tasks;
                     }
                 } break;
@@ -18935,7 +19918,8 @@ struct ggml_cplan ggml_graph_plan(const struct ggml_cgraph * cgraph, int n_threa
                     const int64_t ne10 = node->src[1]->ne[0];  // L
                     const int64_t ne11 = node->src[1]->ne[1];  // Cin
 
-                    if (node->src[0]->type == GGML_TYPE_F16 &&
+                    if ((node->src[0]->type == GGML_TYPE_F16 ||
+                         node->src[0]->type == GGML_TYPE_BF16) &&
                         node->src[1]->type == GGML_TYPE_F32) {
                         cur += sizeof(ggml_fp16_t)*ne00*ne01*ne02;
                         cur += sizeof(ggml_fp16_t)*ne10*ne11;
@@ -18971,6 +19955,9 @@ struct ggml_cplan ggml_graph_plan(const struct ggml_cgraph * cgraph, int n_threa
                     } else if (node->src[1]->type == GGML_TYPE_F16) {
                         cur  = sizeof(float)*ne11*n_tasks; // TODO: this can become (n_tasks-1)
                         cur += sizeof(float)*ne11*n_tasks; // this is overestimated by x2
+                    } else if (node->src[1]->type == GGML_TYPE_BF16) {
+                        cur  = sizeof(float)*ne11*n_tasks; // TODO: this can become (n_tasks-1)
+                        cur += sizeof(float)*ne11*n_tasks; // this is overestimated by x2
                     }
                 } break;
             case GGML_OP_FLASH_ATTN_EXT:
@@ -18987,6 +19974,9 @@ struct ggml_cplan ggml_graph_plan(const struct ggml_cgraph * cgraph, int n_threa
                     } else if (node->src[1]->type == GGML_TYPE_F16) {
                         cur  = sizeof(float)*node->src[1]->ne[1]*n_tasks; // TODO: this can become (n_tasks-1)
                         cur += sizeof(float)*node->src[1]->ne[1]*n_tasks; // this is overestimated by x2
+                    } else if (node->src[1]->type == GGML_TYPE_BF16) {
+                        cur  = sizeof(float)*node->src[1]->ne[1]*n_tasks; // TODO: this can become (n_tasks-1)
+                        cur += sizeof(float)*node->src[1]->ne[1]*n_tasks; // this is overestimated by x2
                     }
                 } break;
             case GGML_OP_FLASH_ATTN_BACK:
@@ -19000,6 +19990,9 @@ struct ggml_cplan ggml_graph_plan(const struct ggml_cgraph * cgraph, int n_threa
                     } else if (node->src[1]->type == GGML_TYPE_F16) {
                         cur  = sizeof(float)*mxDn*n_tasks; // TODO: this can become (n_tasks-1)
                         cur += sizeof(float)*mxDn*n_tasks; // this is overestimated by x2
+                    } else if (node->src[1]->type == GGML_TYPE_BF16) {
+                        cur  = sizeof(float)*mxDn*n_tasks; // TODO: this can become (n_tasks-1)
+                        cur += sizeof(float)*mxDn*n_tasks; // this is overestimated by x2
                     }
                 } break;
 
@@ -19776,7 +20769,9 @@ void ggml_graph_dump_dot(const struct ggml_cgraph * gb, const struct ggml_cgraph
                 if (node->type == GGML_TYPE_I8 || node->type == GGML_TYPE_I16 || node->type == GGML_TYPE_I32) {
                     fprintf(fp, "%d", ggml_get_i32_1d(node, j));
                 }
-                else if (node->type == GGML_TYPE_F32 || node->type == GGML_TYPE_F16) {
+                else if (node->type == GGML_TYPE_F32 ||
+                         node->type == GGML_TYPE_F16 ||
+                         node->type == GGML_TYPE_BF16) {
                     fprintf(fp, "%.1e", (double)ggml_get_f32_1d(node, j));
                 }
                 else {
@@ -20834,6 +21829,12 @@ size_t ggml_quantize_chunk(
                 ggml_fp32_to_fp16_row(src + start, (ggml_fp16_t *)dst + start, n);
                 result = n * elemsize;
             } break;
+        case GGML_TYPE_BF16:
+            {
+                size_t elemsize = sizeof(ggml_bf16_t);
+                ggml_fp32_to_bf16_row(src + start, (ggml_bf16_t *)dst + start, n);
+                result = n * elemsize;
+            } break;
         case GGML_TYPE_F32:
             {
                 size_t elemsize = sizeof(float);

ggml.h

@@ -326,14 +326,20 @@ extern "C" {
     // get ggml_status name string
     GGML_API GGML_CALL const char * ggml_status_to_string(enum ggml_status status);
 
+    // ieee 754-2008 half-precision float16
+    // todo: make this not an integral type
     typedef uint16_t ggml_fp16_t;
-
-    // convert FP16 <-> FP32
-    GGML_API float       ggml_fp16_to_fp32(ggml_fp16_t x);
-    GGML_API ggml_fp16_t ggml_fp32_to_fp16(float x);
-
-    GGML_API void ggml_fp16_to_fp32_row(const ggml_fp16_t * x, float * y, int64_t n);
-    GGML_API void ggml_fp32_to_fp16_row(const float * x, ggml_fp16_t * y, int64_t n);
+    GGML_API float       ggml_fp16_to_fp32(ggml_fp16_t);
+    GGML_API ggml_fp16_t ggml_fp32_to_fp16(float);
+    GGML_API void        ggml_fp16_to_fp32_row(const ggml_fp16_t *, float *, int64_t);
+    GGML_API void        ggml_fp32_to_fp16_row(const float *, ggml_fp16_t *, int64_t);
+
+    // google brain half-precision bfloat16
+    typedef struct { uint16_t bits; } ggml_bf16_t;
+    GGML_API ggml_bf16_t ggml_fp32_to_bf16(float);
+    GGML_API float       ggml_bf16_to_fp32(ggml_bf16_t);  // consider just doing << 16
+    GGML_API void        ggml_bf16_to_fp32_row(const ggml_bf16_t *, float *, int64_t);
+    GGML_API void        ggml_fp32_to_bf16_row(const float *, ggml_bf16_t *, int64_t);
 
     struct ggml_object;
     struct ggml_context;
@@ -370,6 +376,7 @@ extern "C" {
         GGML_TYPE_I64     = 27,
         GGML_TYPE_F64     = 28,
         GGML_TYPE_IQ1_M   = 29,
+        GGML_TYPE_BF16    = 30,
         GGML_TYPE_COUNT,
     };
 
@@ -410,6 +417,7 @@ extern "C" {
         GGML_FTYPE_MOSTLY_IQ2_S   = 21, // except 1d tensors
         GGML_FTYPE_MOSTLY_IQ4_XS  = 22, // except 1d tensors
         GGML_FTYPE_MOSTLY_IQ1_M   = 23, // except 1d tensors
+        GGML_FTYPE_MOSTLY_BF16    = 24, // except 1d tensors
     };
 
     // available tensor operations: