From 892274d20d5f4d4d1659a2eb6039adecfedc80ee Mon Sep 17 00:00:00 2001
From: Georg Lehmann <dadschoorse@gmail.com>
Date: Wed, 18 Feb 2026 13:21:14 +0100
Subject: [PATCH] ac/llvm: implement mixed float dot
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Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/40003>
---
 src/amd/llvm/ac_nir_to_llvm.c | 53 +++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/src/amd/llvm/ac_nir_to_llvm.c b/src/amd/llvm/ac_nir_to_llvm.c
index c9f1bcfd660..56ae0c47dff 100644
--- a/src/amd/llvm/ac_nir_to_llvm.c
+++ b/src/amd/llvm/ac_nir_to_llvm.c
@@ -1153,6 +1153,21 @@ static bool visit_alu(struct ac_nir_context *ctx, const nir_alu_instr *instr)
       break;
    }
 
+  case nir_op_bfdot2_fadd: {
+      const char *name = "llvm.amdgcn.fdot2.f32.bf16";
+      LLVMTypeRef vec2_type = ctx->ac.v2bf16;
+#if LLVM_VERSION_MAJOR < 19 || (LLVM_VERSION_MAJOR == 19 && LLVM_VERSION_MINOR == 0)
+      /* Before LLVM 19.1, bf16 fdot used integer operands. */
+      vec2_type = ctx->ac.v2i16;
+#endif
+      src[0] = LLVMBuildBitCast(ctx->ac.builder, src[0], vec2_type, "");
+      src[1] = LLVMBuildBitCast(ctx->ac.builder, src[1], vec2_type, "");
+      src[2] = LLVMBuildBitCast(ctx->ac.builder, src[2], ctx->ac.f32, "");
+      src[3] = ctx->ac.i1false; /* clamp */
+      result = ac_build_intrinsic(&ctx->ac, name, ctx->ac.f32, src, 4, 0);
+      break;
+   }
+
    case nir_op_bfdot2_bfadd: {
       const char *name = "llvm.amdgcn.fdot2.bf16.bf16";
       LLVMTypeRef vec2_type = ctx->ac.v2bf16;
@@ -1169,6 +1184,44 @@ static bool visit_alu(struct ac_nir_context *ctx, const nir_alu_instr *instr)
       break;
    }
 
+   case nir_op_f16dot2_fadd: {
+      src[0] = LLVMBuildBitCast(ctx->ac.builder, src[0], ctx->ac.v2f16, "");
+      src[1] = LLVMBuildBitCast(ctx->ac.builder, src[1], ctx->ac.v2f16, "");
+
+      if (instr->def.bit_size == 16) {
+         const char *name = "llvm.amdgcn.fdot2.f16.f16";
+         src[2] = LLVMBuildBitCast(ctx->ac.builder, src[2], ctx->ac.f16, "");
+         result = ac_build_intrinsic(&ctx->ac, name, ctx->ac.f16, src, 3, 0);
+      } else {
+         const char *name = "llvm.amdgcn.fdot2";
+         src[2] = LLVMBuildBitCast(ctx->ac.builder, src[2], ctx->ac.f32, "");
+         src[3] = ctx->ac.i1false; /* clamp */
+         result = ac_build_intrinsic(&ctx->ac, name, ctx->ac.f32, src, 4, 0);
+      }
+      break;
+   }
+
+   case nir_op_e4m3fn_dot4_fadd: {
+      const char *name = "llvm.amdgcn.dot4.f32.fp8.fp8";
+      src[2] = LLVMBuildBitCast(ctx->ac.builder, src[2], ctx->ac.f32, "");
+      result = ac_build_intrinsic(&ctx->ac, name, ctx->ac.f32, src, 3, 0);
+      break;
+   }
+
+   case nir_op_e5m2_dot4_fadd: {
+      const char *name = "llvm.amdgcn.dot4.f32.bf8.bf8";
+      src[2] = LLVMBuildBitCast(ctx->ac.builder, src[2], ctx->ac.f32, "");
+      result = ac_build_intrinsic(&ctx->ac, name, ctx->ac.f32, src, 3, 0);
+      break;
+   }
+
+   case nir_op_e4m3fn_e5m2_dot4_fadd: {
+      const char *name = "llvm.amdgcn.dot4.f32.fp8.bf8";
+      src[2] = LLVMBuildBitCast(ctx->ac.builder, src[2], ctx->ac.f32, "");
+      result = ac_build_intrinsic(&ctx->ac, name, ctx->ac.f32, src, 3, 0);
+      break;
+   }
+
    case nir_op_msad_4x8:
       result = ac_build_intrinsic(&ctx->ac, "llvm.amdgcn.msad.u8", ctx->ac.i32,
                                   (LLVMValueRef[]){src[1], src[0], src[2]}, 3, 0);