[llvm] Revert "[NVPTX] Support copysign PTX instruction (#107800)" (PR #108066)

Tue Sep 10 11:13:38 PDT 2024

llvmbot wrote:




@llvm/pr-subscribers-backend-nvptx

Author: Pranav Kant (pranavk)

<details>
<summary>Changes</summary>

This reverts commit b0d2411b53a0b55baf6d6dc7986d285ce59807fa.

Reverting because the original commit misses case of copysign from a constant.

---
Full diff: https://github.com/llvm/llvm-project/pull/108066.diff


4 Files Affected:

- (modified) llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp (+2-2) 
- (modified) llvm/lib/Target/NVPTX/NVPTXIntrinsics.td (-14) 
- (removed) llvm/test/CodeGen/NVPTX/copysign.ll (-39) 
- (modified) llvm/test/CodeGen/NVPTX/math-intrins.ll (+13-6) 


``````````diff

diff --git a/llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp b/llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp
index 3816e099537199..5c5766a8b23455 100644
--- a/llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp
+++ b/llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp
@@ -838,8 +838,8 @@ NVPTXTargetLowering::NVPTXTargetLowering(const NVPTXTargetMachine &TM,
   setOperationAction(ISD::FCOPYSIGN, MVT::v2f16, Expand);
   setOperationAction(ISD::FCOPYSIGN, MVT::bf16, Expand);
   setOperationAction(ISD::FCOPYSIGN, MVT::v2bf16, Expand);
-  setOperationAction(ISD::FCOPYSIGN, MVT::f32, Legal);
-  setOperationAction(ISD::FCOPYSIGN, MVT::f64, Legal);
+  setOperationAction(ISD::FCOPYSIGN, MVT::f32, Expand);
+  setOperationAction(ISD::FCOPYSIGN, MVT::f64, Expand);
 
   // These map to corresponding instructions for f32/f64. f16 must be
   // promoted to f32. v2f16 is expanded to f16, which is then promoted
diff --git a/llvm/lib/Target/NVPTX/NVPTXIntrinsics.td b/llvm/lib/Target/NVPTX/NVPTXIntrinsics.td
index e8e8548120131e..0c883093dd0a54 100644
--- a/llvm/lib/Target/NVPTX/NVPTXIntrinsics.td
+++ b/llvm/lib/Target/NVPTX/NVPTXIntrinsics.td
@@ -977,20 +977,6 @@ def INT_NVVM_FABS_F : F_MATH_1<"abs.f32 \t$dst, $src0;", Float32Regs,
 def INT_NVVM_FABS_D : F_MATH_1<"abs.f64 \t$dst, $src0;", Float64Regs,
   Float64Regs, int_nvvm_fabs_d>;
 
-//
-// copysign
-//
-
-def COPYSIGN_F :
-    NVPTXInst<(outs Float32Regs:$dst), (ins Float32Regs:$src0, Float32Regs:$src1),
-              "copysign.f32 \t$dst, $src0, $src1;",
-              [(set Float32Regs:$dst, (fcopysign Float32Regs:$src1, Float32Regs:$src0))]>;
-
-def COPYSIGN_D :
-    NVPTXInst<(outs Float64Regs:$dst), (ins Float64Regs:$src0, Float64Regs:$src1),
-              "copysign.f64 \t$dst, $src0, $src1;",
-              [(set Float64Regs:$dst, (fcopysign Float64Regs:$src1, Float64Regs:$src0))]>;
-
 //
 // Abs, Neg bf16, bf16x2
 //
diff --git a/llvm/test/CodeGen/NVPTX/copysign.ll b/llvm/test/CodeGen/NVPTX/copysign.ll
deleted file mode 100644
index 96fb37a129b207..00000000000000
--- a/llvm/test/CodeGen/NVPTX/copysign.ll
+++ /dev/null
@@ -1,39 +0,0 @@
-; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
-; RUN: llc < %s -march=nvptx64 -mcpu=sm_20 -verify-machineinstrs | FileCheck %s
-; RUN: %if ptxas %{ llc < %s -march=nvptx64 -mcpu=sm_20 -verify-machineinstrs | %ptxas-verify %}
-
-target triple = "nvptx64-nvidia-cuda"
-target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v16:16:16-v32:32:32-v64:64:64-v128:128:128-n16:32:64"
-
-define float @fcopysign_f(float %a, float %b) {
-; CHECK-LABEL: fcopysign_f(
-; CHECK:       {
-; CHECK-NEXT:    .reg .f32 %f<4>;
-; CHECK-EMPTY:
-; CHECK-NEXT:  // %bb.0:
-; CHECK-NEXT:    ld.param.f32 %f1, [fcopysign_f_param_0];
-; CHECK-NEXT:    ld.param.f32 %f2, [fcopysign_f_param_1];
-; CHECK-NEXT:    copysign.f32 %f3, %f2, %f1;
-; CHECK-NEXT:    st.param.f32 [func_retval0+0], %f3;
-; CHECK-NEXT:    ret;
-  %val = call float @llvm.copysign.f32(float %a, float %b)
-  ret float %val
-}
-
-define double @fcopysign_d(double %a, double %b) {
-; CHECK-LABEL: fcopysign_d(
-; CHECK:       {
-; CHECK-NEXT:    .reg .f64 %fd<4>;
-; CHECK-EMPTY:
-; CHECK-NEXT:  // %bb.0:
-; CHECK-NEXT:    ld.param.f64 %fd1, [fcopysign_d_param_0];
-; CHECK-NEXT:    ld.param.f64 %fd2, [fcopysign_d_param_1];
-; CHECK-NEXT:    copysign.f64 %fd3, %fd2, %fd1;
-; CHECK-NEXT:    st.param.f64 [func_retval0+0], %fd3;
-; CHECK-NEXT:    ret;
-  %val = call double @llvm.copysign.f64(double %a, double %b)
-  ret double %val
-}
-
-declare float @llvm.copysign.f32(float, float)
-declare double @llvm.copysign.f64(double, double)
diff --git a/llvm/test/CodeGen/NVPTX/math-intrins.ll b/llvm/test/CodeGen/NVPTX/math-intrins.ll
index bdd6c914384601..fcc4ec6e4017f7 100644
--- a/llvm/test/CodeGen/NVPTX/math-intrins.ll
+++ b/llvm/test/CodeGen/NVPTX/math-intrins.ll
@@ -195,8 +195,9 @@ define double @round_double(double %a) {
 ; check the use of 0.5 to implement round
 ; CHECK-LABEL: round_double(
 ; CHECK:       {
-; CHECK-NEXT:    .reg .pred %p<3>;
-; CHECK-NEXT:    .reg .f64 %fd<8>;
+; CHECK-NEXT:    .reg .pred %p<4>;
+; CHECK-NEXT:    .reg .b64 %rd<4>;
+; CHECK-NEXT:    .reg .f64 %fd<10>;
 ; CHECK-EMPTY:
 ; CHECK-NEXT:  // %bb.0:
 ; CHECK-NEXT:    ld.param.f64 %fd1, [round_double_param_0];
@@ -205,10 +206,16 @@ define double @round_double(double %a) {
 ; CHECK-NEXT:    add.rn.f64 %fd3, %fd2, 0d3FE0000000000000;
 ; CHECK-NEXT:    cvt.rzi.f64.f64 %fd4, %fd3;
 ; CHECK-NEXT:    selp.f64 %fd5, 0d0000000000000000, %fd4, %p1;
-; CHECK-NEXT:    copysign.f64 %fd6, %fd1, %fd5;
-; CHECK-NEXT:    setp.gt.f64 %p2, %fd2, 0d4330000000000000;
-; CHECK-NEXT:    selp.f64 %fd7, %fd1, %fd6, %p2;
-; CHECK-NEXT:    st.param.f64 [func_retval0+0], %fd7;
+; CHECK-NEXT:    abs.f64 %fd6, %fd5;
+; CHECK-NEXT:    neg.f64 %fd7, %fd6;
+; CHECK-NEXT:    mov.b64 %rd1, %fd1;
+; CHECK-NEXT:    shr.u64 %rd2, %rd1, 63;
+; CHECK-NEXT:    and.b64 %rd3, %rd2, 1;
+; CHECK-NEXT:    setp.eq.b64 %p2, %rd3, 1;
+; CHECK-NEXT:    selp.f64 %fd8, %fd7, %fd6, %p2;
+; CHECK-NEXT:    setp.gt.f64 %p3, %fd2, 0d4330000000000000;
+; CHECK-NEXT:    selp.f64 %fd9, %fd1, %fd8, %p3;
+; CHECK-NEXT:    st.param.f64 [func_retval0+0], %fd9;
 ; CHECK-NEXT:    ret;
   %b = call double @llvm.round.f64(double %a)
   ret double %b

``````````

</details>


https://github.com/llvm/llvm-project/pull/108066
