[clang] [llvm] [AMDGPU] Add GFX12 WMMA and SWMMAC instructions (PR #77795)

[Matt Arsenault via cfe-commits]

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@@ -423,6 +423,67 @@ TARGET_BUILTIN(__builtin_amdgcn_s_wakeup_barrier, "vi", "n", "gfx12-insts")
 TARGET_BUILTIN(__builtin_amdgcn_s_barrier_leave, "b", "n", "gfx12-insts")
 TARGET_BUILTIN(__builtin_amdgcn_s_get_barrier_state, "Uii", "n", "gfx12-insts")
 
+//===----------------------------------------------------------------------===//
+// WMMA builtins.
+// Postfix w32 indicates the builtin requires wavefront size of 32.
+// Postfix w64 indicates the builtin requires wavefront size of 64.
+//
+// Some of these are very similar to their GFX11 counterparts, but they don't
+// require replication of the A,B matrices, so they use fewer vector elements.
+// Therefore, we add an "_gfx12" suffix to distinguish them from the existing
+// builtins.
+//===----------------------------------------------------------------------===//
+TARGET_BUILTIN(__builtin_amdgcn_wmma_f32_16x16x16_f16_w32_gfx12, "V8fV8hV8hV8f", "nc", "gfx12-insts,wavefrontsize32")
+TARGET_BUILTIN(__builtin_amdgcn_wmma_f32_16x16x16_bf16_w32_gfx12, "V8fV8sV8sV8f", "nc", "gfx12-insts,wavefrontsize32")
+TARGET_BUILTIN(__builtin_amdgcn_wmma_f16_16x16x16_f16_w32_gfx12, "V8hV8hV8hV8h", "nc", "gfx12-insts,wavefrontsize32")
+TARGET_BUILTIN(__builtin_amdgcn_wmma_bf16_16x16x16_bf16_w32_gfx12, "V8sV8sV8sV8s", "nc", "gfx12-insts,wavefrontsize32")
+TARGET_BUILTIN(__builtin_amdgcn_wmma_i32_16x16x16_iu8_w32_gfx12, "V8iIbV2iIbV2iV8iIb", "nc", "gfx12-insts,wavefrontsize32")
+TARGET_BUILTIN(__builtin_amdgcn_wmma_i32_16x16x16_iu4_w32_gfx12, "V8iIbiIbiV8iIb", "nc", "gfx12-insts,wavefrontsize32")
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arsenm wrote:

the signed-unsigned fusion with control bit is a bit ugly, would have been nicer to have separate signed and unsigned variants with the types changed. I suppose this was already the mistake made with the gfx11 builtins though 

https://github.com/llvm/llvm-project/pull/77795