[AMDGPU] Add v_fma_mix_f32_f16 as an alias of v_fma_mix_f32 on gfx1250 (#150502)

Co-authored-by: Jay Foad <[email protected]>

Author: changpeng

llvm/lib/Target/AMDGPU/VOP3PInstructions.td

@@ -2277,6 +2277,9 @@ defm V_FMA_MIX_F32_BF16 : VOP3P_Realtriple<GFX1250Gen, 0x3d>;
 defm V_FMA_MIXLO_BF16   : VOP3P_Realtriple<GFX1250Gen, 0x3e>;
 defm V_FMA_MIXHI_BF16   : VOP3P_Realtriple<GFX1250Gen, 0x3f>;
 
+let AssemblerPredicate = isGFX1250Plus in
+def : AMDGPUMnemonicAlias<"v_fma_mix_f32_f16",  "v_fma_mix_f32">;
+
 defm V_PK_MINIMUM_F16 : VOP3P_Real_gfx12<0x1d>;
 defm V_PK_MAXIMUM_F16 : VOP3P_Real_gfx12<0x1e>;
 

llvm/test/MC/AMDGPU/gfx1250_asm_vop3p_alias.s

@@ -0,0 +1,5 @@
+// NOTE: Assertions have been autogenerated by utils/update_mc_test_checks.py UTC_ARGS: --version 5
+// RUN: llvm-mc -triple=amdgcn -mcpu=gfx1250 -show-encoding < %s | FileCheck --check-prefix=GFX1250 %s
+
+v_fma_mix_f32_f16 v5, v1, v2, s3
+// GFX1250: v_fma_mix_f32 v5, v1, v2, s3            ; encoding: [0x05,0x00,0x20,0xcc,0x01,0x05,0x0e,0x00]