[llvm] [AMDGPU] Fixed byte_sel of v_cvt_f32_bf8/v_cvt_f32_fp8 (PR #80502)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-amdgpu

Author: Stanislav Mekhanoshin (rampitec)

<details>
<summary>Changes</summary>

Opsel bits are swapped. Actual byte select table:

Byte  OPSEL
0     0
1     2
2     1
3     3

---
Full diff: https://github.com/llvm/llvm-project/pull/80502.diff


3 Files Affected:

- (modified) llvm/lib/Target/AMDGPU/VOP1Instructions.td (+2-4) 
- (modified) llvm/test/CodeGen/AMDGPU/llvm.amdgcn.cvt.fp8.dpp.ll (+2-2) 
- (modified) llvm/test/CodeGen/AMDGPU/llvm.amdgcn.cvt.fp8.ll (+4-4) 


``````````diff
diff --git a/llvm/lib/Target/AMDGPU/VOP1Instructions.td b/llvm/lib/Target/AMDGPU/VOP1Instructions.td
index 920c220fb2c65..58b67b21e274b 100644
--- a/llvm/lib/Target/AMDGPU/VOP1Instructions.td
+++ b/llvm/lib/Target/AMDGPU/VOP1Instructions.td
@@ -668,10 +668,8 @@ class Cvt_F32_F8_Pat_OpSel<SDPatternOperator node, bits<2> index,
     VOP1_Pseudo inst_e32, VOP3_Pseudo inst_e64> : GCNPat<
     (f32 (node i32:$src, index)),
     !if (index,
-         (inst_e64 !if(index{0},
-                         !if(index{1}, !or(SRCMODS.OP_SEL_0, SRCMODS.OP_SEL_1),
-                                       SRCMODS.OP_SEL_0),
-                         !if(index{1}, SRCMODS.OP_SEL_1, 0)),
+         (inst_e64 !or(!if(index{0}, SRCMODS.OP_SEL_1, 0),
+                       !if(index{1}, SRCMODS.OP_SEL_0, 0)),
                     $src, 0),
          (inst_e32 $src))
 >;
diff --git a/llvm/test/CodeGen/AMDGPU/llvm.amdgcn.cvt.fp8.dpp.ll b/llvm/test/CodeGen/AMDGPU/llvm.amdgcn.cvt.fp8.dpp.ll
index f49fec60892cd..e21d61036375a 100644
--- a/llvm/test/CodeGen/AMDGPU/llvm.amdgcn.cvt.fp8.dpp.ll
+++ b/llvm/test/CodeGen/AMDGPU/llvm.amdgcn.cvt.fp8.dpp.ll
@@ -16,7 +16,7 @@ define amdgpu_cs float @test_cvt_f32_bf8_byte1(i32 %a) {
 ; GFX12:       ; %bb.0:
 ; GFX12-NEXT:    v_mov_b32_dpp v0, v0 quad_perm:[0,1,2,3] row_mask:0xf bank_mask:0xf bound_ctrl:1
 ; GFX12-NEXT:    s_delay_alu instid0(VALU_DEP_1)
-; GFX12-NEXT:    v_cvt_f32_bf8_e64 v0, v0 op_sel:[1,0]
+; GFX12-NEXT:    v_cvt_f32_bf8_e64 v0, v0 op_sel:[0,1]
 ; GFX12-NEXT:    ; return to shader part epilog
   %tmp0 = call i32 @llvm.amdgcn.mov.dpp.i32(i32 %a, i32 228, i32 15, i32 15, i1 1)
   %ret = tail call float @llvm.amdgcn.cvt.f32.bf8(i32 %tmp0, i32 1)
@@ -28,7 +28,7 @@ define amdgpu_cs float @test_cvt_f32_bf8_byte2(i32 %a) {
 ; GFX12:       ; %bb.0:
 ; GFX12-NEXT:    v_mov_b32_dpp v0, v0 quad_perm:[0,1,2,3] row_mask:0xf bank_mask:0xf bound_ctrl:1
 ; GFX12-NEXT:    s_delay_alu instid0(VALU_DEP_1)
-; GFX12-NEXT:    v_cvt_f32_bf8_e64 v0, v0 op_sel:[0,1]
+; GFX12-NEXT:    v_cvt_f32_bf8_e64 v0, v0 op_sel:[1,0]
 ; GFX12-NEXT:    ; return to shader part epilog
   %tmp0 = call i32 @llvm.amdgcn.mov.dpp.i32(i32 %a, i32 228, i32 15, i32 15, i1 1)
   %ret = tail call float @llvm.amdgcn.cvt.f32.bf8(i32 %tmp0, i32 2)
diff --git a/llvm/test/CodeGen/AMDGPU/llvm.amdgcn.cvt.fp8.ll b/llvm/test/CodeGen/AMDGPU/llvm.amdgcn.cvt.fp8.ll
index 17b1fcf865e94..f915fa8e6cd1c 100644
--- a/llvm/test/CodeGen/AMDGPU/llvm.amdgcn.cvt.fp8.ll
+++ b/llvm/test/CodeGen/AMDGPU/llvm.amdgcn.cvt.fp8.ll
@@ -45,7 +45,7 @@ define float @test_cvt_f32_bf8_byte1(i32 %a) {
 ; GFX12-NEXT:    s_wait_samplecnt 0x0
 ; GFX12-NEXT:    s_wait_bvhcnt 0x0
 ; GFX12-NEXT:    s_wait_kmcnt 0x0
-; GFX12-NEXT:    v_cvt_f32_bf8_e64 v0, v0 op_sel:[1,0]
+; GFX12-NEXT:    v_cvt_f32_bf8_e64 v0, v0 op_sel:[0,1]
 ; GFX12-NEXT:    s_setpc_b64 s[30:31]
   %ret = tail call float @llvm.amdgcn.cvt.f32.bf8(i32 %a, i32 1)
   ret float %ret
@@ -65,7 +65,7 @@ define float @test_cvt_f32_bf8_byte2(i32 %a) {
 ; GFX12-NEXT:    s_wait_samplecnt 0x0
 ; GFX12-NEXT:    s_wait_bvhcnt 0x0
 ; GFX12-NEXT:    s_wait_kmcnt 0x0
-; GFX12-NEXT:    v_cvt_f32_bf8_e64 v0, v0 op_sel:[0,1]
+; GFX12-NEXT:    v_cvt_f32_bf8_e64 v0, v0 op_sel:[1,0]
 ; GFX12-NEXT:    s_setpc_b64 s[30:31]
   %ret = tail call float @llvm.amdgcn.cvt.f32.bf8(i32 %a, i32 2)
   ret float %ret
@@ -125,7 +125,7 @@ define float @test_cvt_f32_fp8_byte1(i32 %a) {
 ; GFX12-NEXT:    s_wait_samplecnt 0x0
 ; GFX12-NEXT:    s_wait_bvhcnt 0x0
 ; GFX12-NEXT:    s_wait_kmcnt 0x0
-; GFX12-NEXT:    v_cvt_f32_fp8_e64 v0, v0 op_sel:[1,0]
+; GFX12-NEXT:    v_cvt_f32_fp8_e64 v0, v0 op_sel:[0,1]
 ; GFX12-NEXT:    s_setpc_b64 s[30:31]
   %ret = tail call float @llvm.amdgcn.cvt.f32.fp8(i32 %a, i32 1)
   ret float %ret
@@ -145,7 +145,7 @@ define float @test_cvt_f32_fp8_byte2(i32 %a) {
 ; GFX12-NEXT:    s_wait_samplecnt 0x0
 ; GFX12-NEXT:    s_wait_bvhcnt 0x0
 ; GFX12-NEXT:    s_wait_kmcnt 0x0
-; GFX12-NEXT:    v_cvt_f32_fp8_e64 v0, v0 op_sel:[0,1]
+; GFX12-NEXT:    v_cvt_f32_fp8_e64 v0, v0 op_sel:[1,0]
 ; GFX12-NEXT:    s_setpc_b64 s[30:31]
   %ret = tail call float @llvm.amdgcn.cvt.f32.fp8(i32 %a, i32 2)
   ret float %ret

``````````

</details>


https://github.com/llvm/llvm-project/pull/80502