[llvm] [AMDGPU] Fix gfx950 Trans32 latency (PR #156411)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-amdgpu

Author: Austin Kerbow (kerbowa)

<details>
<summary>Changes</summary>

Updated from 4->2 on gfx950

---
Full diff: https://github.com/llvm/llvm-project/pull/156411.diff


2 Files Affected:

- (modified) llvm/lib/Target/AMDGPU/SISchedule.td (+5-1) 
- (modified) llvm/test/CodeGen/AMDGPU/bf16.ll (+6-6) 


``````````diff
diff --git a/llvm/lib/Target/AMDGPU/SISchedule.td b/llvm/lib/Target/AMDGPU/SISchedule.td
index 8eecb1c1019ae..9319d43e2ce1f 100644
--- a/llvm/lib/Target/AMDGPU/SISchedule.td
+++ b/llvm/lib/Target/AMDGPU/SISchedule.td
@@ -172,7 +172,6 @@ multiclass SICommonWriteRes {
 
   def : HWVALUWriteRes<Write32Bit,         1>;
   def : HWVALUWriteRes<WriteFloatCvt,      4>;
-  def : HWVALUWriteRes<WriteTrans32,       4>;
   def : HWVALUWriteRes<WriteQuarterRate32, 4>;
 
   let ReleaseAtCycles = [4] in
@@ -231,6 +230,7 @@ def : HWVALUWriteRes<WriteFloatFMA,    1>;
 def : HWVALUWriteRes<WriteDouble,      4>;
 def : HWVALUWriteRes<WriteDoubleAdd,   2>;
 def : HWVALUWriteRes<WriteDoubleCvt,   4>;
+def : HWVALUWriteRes<WriteTrans32,     4>;
 def : HWVALUWriteRes<WriteTrans64,     4>;
 } // End RetireOOO = 1
 
@@ -249,6 +249,7 @@ def : HWVALUWriteRes<WriteFloatFMA,    16>;
 def : HWVALUWriteRes<WriteDouble,      16>;
 def : HWVALUWriteRes<WriteDoubleAdd,    8>;
 def : HWVALUWriteRes<WriteDoubleCvt,    4>;
+def : HWVALUWriteRes<WriteTrans32,     4>;
 def : HWVALUWriteRes<WriteTrans64,     16>;
 } // End RetireOOO = 1
 
@@ -269,6 +270,7 @@ def : HWVALUWriteRes<WriteFloatFMA,    1>;
 def : HWVALUWriteRes<WriteDouble,      1>;
 def : HWVALUWriteRes<WriteDoubleAdd,   1>;
 def : HWVALUWriteRes<WriteDoubleCvt,   1>;
+def : HWVALUWriteRes<WriteTrans32,     4>;
 def : HWVALUWriteRes<WriteTrans64,     4>;
 def : HWVALUWriteRes<WriteIntMul,      1>;
 def : HWVALUWriteRes<Write64Bit,       1>;
@@ -292,6 +294,7 @@ def : HWVALUWriteRes<WriteFloatFMA,    1>;
 def : HWVALUWriteRes<WriteDouble,      1>;
 def : HWVALUWriteRes<WriteDoubleAdd,   1>;
 def : HWVALUWriteRes<WriteDoubleCvt,   1>;
+def : HWVALUWriteRes<WriteTrans32,     4>;
 def : HWVALUWriteRes<WriteTrans64,     4>;
 def : HWVALUWriteRes<WriteIntMul,      1>;
 def : HWVALUWriteRes<Write64Bit,       1>;
@@ -326,6 +329,7 @@ def : HWVALUWriteRes<WriteFloatFMA,    1>;
 def : HWVALUWriteRes<WriteDouble,      1>;
 def : HWVALUWriteRes<WriteDoubleAdd,   1>;
 def : HWVALUWriteRes<WriteDoubleCvt,   1>;
+def : HWVALUWriteRes<WriteTrans32,     2>;
 def : HWVALUWriteRes<WriteTrans64,     4>;
 def : HWVALUWriteRes<WriteIntMul,      1>;
 def : HWVALUWriteRes<Write64Bit,       1>;
diff --git a/llvm/test/CodeGen/AMDGPU/bf16.ll b/llvm/test/CodeGen/AMDGPU/bf16.ll
index 10e523d1a0cf1..e8a4329e7f5cf 100644
--- a/llvm/test/CodeGen/AMDGPU/bf16.ll
+++ b/llvm/test/CodeGen/AMDGPU/bf16.ll
@@ -30434,15 +30434,15 @@ define bfloat @v_exp_bf16(bfloat %a) {
 ; GFX950-NEXT:    v_sub_f32_e32 v3, v1, v2
 ; GFX950-NEXT:    v_fma_f32 v1, v0, s0, -v1
 ; GFX950-NEXT:    v_fmamk_f32 v1, v0, 0x32a5705f, v1
+; GFX950-NEXT:    v_cvt_i32_f32_e32 v2, v2
 ; GFX950-NEXT:    v_add_f32_e32 v1, v3, v1
 ; GFX950-NEXT:    v_exp_f32_e32 v1, v1
-; GFX950-NEXT:    v_cvt_i32_f32_e32 v2, v2
 ; GFX950-NEXT:    s_mov_b32 s0, 0xc2ce8ed0
+; GFX950-NEXT:    v_ldexp_f32 v1, v1, v2
 ; GFX950-NEXT:    v_cmp_ngt_f32_e32 vcc, s0, v0
 ; GFX950-NEXT:    s_mov_b32 s0, 0x42b17218
-; GFX950-NEXT:    v_ldexp_f32 v1, v1, v2
-; GFX950-NEXT:    v_cndmask_b32_e32 v1, 0, v1, vcc
 ; GFX950-NEXT:    v_mov_b32_e32 v2, 0x7f800000
+; GFX950-NEXT:    v_cndmask_b32_e32 v1, 0, v1, vcc
 ; GFX950-NEXT:    v_cmp_nlt_f32_e32 vcc, s0, v0
 ; GFX950-NEXT:    s_nop 1
 ; GFX950-NEXT:    v_cndmask_b32_e32 v0, v2, v1, vcc
@@ -30834,15 +30834,15 @@ define bfloat @v_exp10_bf16(bfloat %a) {
 ; GFX950-NEXT:    v_sub_f32_e32 v3, v1, v2
 ; GFX950-NEXT:    v_fma_f32 v1, v0, s0, -v1
 ; GFX950-NEXT:    v_fmamk_f32 v1, v0, 0x33979a37, v1
+; GFX950-NEXT:    v_cvt_i32_f32_e32 v2, v2
 ; GFX950-NEXT:    v_add_f32_e32 v1, v3, v1
 ; GFX950-NEXT:    v_exp_f32_e32 v1, v1
-; GFX950-NEXT:    v_cvt_i32_f32_e32 v2, v2
 ; GFX950-NEXT:    s_mov_b32 s0, 0xc23369f4
+; GFX950-NEXT:    v_ldexp_f32 v1, v1, v2
 ; GFX950-NEXT:    v_cmp_ngt_f32_e32 vcc, s0, v0
 ; GFX950-NEXT:    s_mov_b32 s0, 0x421a209b
-; GFX950-NEXT:    v_ldexp_f32 v1, v1, v2
-; GFX950-NEXT:    v_cndmask_b32_e32 v1, 0, v1, vcc
 ; GFX950-NEXT:    v_mov_b32_e32 v2, 0x7f800000
+; GFX950-NEXT:    v_cndmask_b32_e32 v1, 0, v1, vcc
 ; GFX950-NEXT:    v_cmp_nlt_f32_e32 vcc, s0, v0
 ; GFX950-NEXT:    s_nop 1
 ; GFX950-NEXT:    v_cndmask_b32_e32 v0, v2, v1, vcc

``````````

</details>


https://github.com/llvm/llvm-project/pull/156411