[LLVM][DAGCombine] Remove combiner-vector-fcopysign-extend-round. (#129878)

This option was added to improve test coverage for SVE lowering code
that is impossible to reach otherwise. Given it is not possible to
trigger a bug without it and the generated code is universally worse
with it, I figure the option has no value and should be removed.

Author: paulwalker-arm

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

@@ -149,10 +149,6 @@ static cl::opt<bool> EnableShrinkLoadReplaceStoreWithStore(
     cl::desc("DAG combiner enable load/<replace bytes>/store with "
              "a narrower store"));
 
-static cl::opt<bool> EnableVectorFCopySignExtendRound(
-    "combiner-vector-fcopysign-extend-round", cl::Hidden, cl::init(false),
-    cl::desc(
-        "Enable merging extends and rounds into FCOPYSIGN on vector types"));
 namespace {
 
   class DAGCombiner {
@@ -18011,7 +18007,8 @@ static inline bool CanCombineFCOPYSIGN_EXTEND_ROUND(EVT XTy, EVT YTy) {
   if (YTy == MVT::f128)
     return false;
 
-  return !YTy.isVector() || EnableVectorFCopySignExtendRound;
+  // Avoid mismatched vector operand types, for better instruction selection.
+  return !YTy.isVector();
 }
 
 static inline bool CanCombineFCOPYSIGN_EXTEND_ROUND(SDNode *N) {

llvm/test/CodeGen/AArch64/sve-fcopysign.ll

@@ -1,6 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc < %s -mtriple=aarch64 -mattr=+sve -o - | FileCheck --check-prefixes=CHECK,CHECK-NO-EXTEND-ROUND %s
-; RUN: llc < %s -mtriple=aarch64 -mattr=+sve --combiner-vector-fcopysign-extend-round -o - | FileCheck --check-prefixes=CHECK,CHECK-EXTEND-ROUND %s
+; RUN: llc < %s -mtriple=aarch64 -mattr=+sve -o - | FileCheck %s
 target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
 
 ;============ v2f32
@@ -47,32 +46,16 @@ define <vscale x 4 x float> @test_copysign_v4f32_v4f32(<vscale x 4 x float> %a,
 
 ; SplitVecOp #1
 define <vscale x 4 x float> @test_copysign_v4f32_v4f64(<vscale x 4 x float> %a, <vscale x 4 x double> %b) #0 {
-; CHECK-NO-EXTEND-ROUND-LABEL: test_copysign_v4f32_v4f64:
-; CHECK-NO-EXTEND-ROUND:       // %bb.0:
-; CHECK-NO-EXTEND-ROUND-NEXT:    ptrue p0.d
-; CHECK-NO-EXTEND-ROUND-NEXT:    and z0.s, z0.s, #0x7fffffff
-; CHECK-NO-EXTEND-ROUND-NEXT:    fcvt z2.s, p0/m, z2.d
-; CHECK-NO-EXTEND-ROUND-NEXT:    fcvt z1.s, p0/m, z1.d
-; CHECK-NO-EXTEND-ROUND-NEXT:    uzp1 z1.s, z1.s, z2.s
-; CHECK-NO-EXTEND-ROUND-NEXT:    and z1.s, z1.s, #0x80000000
-; CHECK-NO-EXTEND-ROUND-NEXT:    orr z0.d, z0.d, z1.d
-; CHECK-NO-EXTEND-ROUND-NEXT:    ret
-;
-; CHECK-EXTEND-ROUND-LABEL: test_copysign_v4f32_v4f64:
-; CHECK-EXTEND-ROUND:       // %bb.0:
-; CHECK-EXTEND-ROUND-NEXT:    ptrue p0.d
-; CHECK-EXTEND-ROUND-NEXT:    uunpkhi z3.d, z0.s
-; CHECK-EXTEND-ROUND-NEXT:    uunpklo z0.d, z0.s
-; CHECK-EXTEND-ROUND-NEXT:    fcvt z2.s, p0/m, z2.d
-; CHECK-EXTEND-ROUND-NEXT:    fcvt z1.s, p0/m, z1.d
-; CHECK-EXTEND-ROUND-NEXT:    and z3.s, z3.s, #0x7fffffff
-; CHECK-EXTEND-ROUND-NEXT:    and z0.s, z0.s, #0x7fffffff
-; CHECK-EXTEND-ROUND-NEXT:    and z2.s, z2.s, #0x80000000
-; CHECK-EXTEND-ROUND-NEXT:    and z1.s, z1.s, #0x80000000
-; CHECK-EXTEND-ROUND-NEXT:    orr z2.d, z3.d, z2.d
-; CHECK-EXTEND-ROUND-NEXT:    orr z0.d, z0.d, z1.d
-; CHECK-EXTEND-ROUND-NEXT:    uzp1 z0.s, z0.s, z2.s
-; CHECK-EXTEND-ROUND-NEXT:    ret
+; CHECK-LABEL: test_copysign_v4f32_v4f64:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    ptrue p0.d
+; CHECK-NEXT:    and z0.s, z0.s, #0x7fffffff
+; CHECK-NEXT:    fcvt z2.s, p0/m, z2.d
+; CHECK-NEXT:    fcvt z1.s, p0/m, z1.d
+; CHECK-NEXT:    uzp1 z1.s, z1.s, z2.s
+; CHECK-NEXT:    and z1.s, z1.s, #0x80000000
+; CHECK-NEXT:    orr z0.d, z0.d, z1.d
+; CHECK-NEXT:    ret
   %tmp0 = fptrunc <vscale x 4 x double> %b to <vscale x 4 x float>
   %r = call <vscale x 4 x float> @llvm.copysign.v4f32(<vscale x 4 x float> %a, <vscale x 4 x float> %tmp0)
   ret <vscale x 4 x float> %r
@@ -177,32 +160,16 @@ define <vscale x 4 x half> @test_copysign_v4f16_v4f32(<vscale x 4 x half> %a, <v
 }
 
 define <vscale x 4 x half> @test_copysign_v4f16_v4f64(<vscale x 4 x half> %a, <vscale x 4 x double> %b) #0 {
-; CHECK-NO-EXTEND-ROUND-LABEL: test_copysign_v4f16_v4f64:
-; CHECK-NO-EXTEND-ROUND:       // %bb.0:
-; CHECK-NO-EXTEND-ROUND-NEXT:    ptrue p0.d
-; CHECK-NO-EXTEND-ROUND-NEXT:    and z0.h, z0.h, #0x7fff
-; CHECK-NO-EXTEND-ROUND-NEXT:    fcvt z2.h, p0/m, z2.d
-; CHECK-NO-EXTEND-ROUND-NEXT:    fcvt z1.h, p0/m, z1.d
-; CHECK-NO-EXTEND-ROUND-NEXT:    uzp1 z1.s, z1.s, z2.s
-; CHECK-NO-EXTEND-ROUND-NEXT:    and z1.h, z1.h, #0x8000
-; CHECK-NO-EXTEND-ROUND-NEXT:    orr z0.d, z0.d, z1.d
-; CHECK-NO-EXTEND-ROUND-NEXT:    ret
-;
-; CHECK-EXTEND-ROUND-LABEL: test_copysign_v4f16_v4f64:
-; CHECK-EXTEND-ROUND:       // %bb.0:
-; CHECK-EXTEND-ROUND-NEXT:    ptrue p0.d
-; CHECK-EXTEND-ROUND-NEXT:    uunpkhi z3.d, z0.s
-; CHECK-EXTEND-ROUND-NEXT:    uunpklo z0.d, z0.s
-; CHECK-EXTEND-ROUND-NEXT:    fcvt z2.h, p0/m, z2.d
-; CHECK-EXTEND-ROUND-NEXT:    fcvt z1.h, p0/m, z1.d
-; CHECK-EXTEND-ROUND-NEXT:    and z3.h, z3.h, #0x7fff
-; CHECK-EXTEND-ROUND-NEXT:    and z0.h, z0.h, #0x7fff
-; CHECK-EXTEND-ROUND-NEXT:    and z2.h, z2.h, #0x8000
-; CHECK-EXTEND-ROUND-NEXT:    and z1.h, z1.h, #0x8000
-; CHECK-EXTEND-ROUND-NEXT:    orr z2.d, z3.d, z2.d
-; CHECK-EXTEND-ROUND-NEXT:    orr z0.d, z0.d, z1.d
-; CHECK-EXTEND-ROUND-NEXT:    uzp1 z0.s, z0.s, z2.s
-; CHECK-EXTEND-ROUND-NEXT:    ret
+; CHECK-LABEL: test_copysign_v4f16_v4f64:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    ptrue p0.d
+; CHECK-NEXT:    and z0.h, z0.h, #0x7fff
+; CHECK-NEXT:    fcvt z2.h, p0/m, z2.d
+; CHECK-NEXT:    fcvt z1.h, p0/m, z1.d
+; CHECK-NEXT:    uzp1 z1.s, z1.s, z2.s
+; CHECK-NEXT:    and z1.h, z1.h, #0x8000
+; CHECK-NEXT:    orr z0.d, z0.d, z1.d
+; CHECK-NEXT:    ret
   %tmp0 = fptrunc <vscale x 4 x double> %b to <vscale x 4 x half>
   %r = call <vscale x 4 x half> @llvm.copysign.v4f16(<vscale x 4 x half> %a, <vscale x 4 x half> %tmp0)
   ret <vscale x 4 x half> %r
@@ -224,32 +191,16 @@ define <vscale x 8 x half> @test_copysign_v8f16_v8f16(<vscale x 8 x half> %a, <v
 }
 
 define <vscale x 8 x half> @test_copysign_v8f16_v8f32(<vscale x 8 x half> %a, <vscale x 8 x float> %b) #0 {
-; CHECK-NO-EXTEND-ROUND-LABEL: test_copysign_v8f16_v8f32:
-; CHECK-NO-EXTEND-ROUND:       // %bb.0:
-; CHECK-NO-EXTEND-ROUND-NEXT:    ptrue p0.s
-; CHECK-NO-EXTEND-ROUND-NEXT:    and z0.h, z0.h, #0x7fff
-; CHECK-NO-EXTEND-ROUND-NEXT:    fcvt z2.h, p0/m, z2.s
-; CHECK-NO-EXTEND-ROUND-NEXT:    fcvt z1.h, p0/m, z1.s
-; CHECK-NO-EXTEND-ROUND-NEXT:    uzp1 z1.h, z1.h, z2.h
-; CHECK-NO-EXTEND-ROUND-NEXT:    and z1.h, z1.h, #0x8000
-; CHECK-NO-EXTEND-ROUND-NEXT:    orr z0.d, z0.d, z1.d
-; CHECK-NO-EXTEND-ROUND-NEXT:    ret
-;
-; CHECK-EXTEND-ROUND-LABEL: test_copysign_v8f16_v8f32:
-; CHECK-EXTEND-ROUND:       // %bb.0:
-; CHECK-EXTEND-ROUND-NEXT:    ptrue p0.s
-; CHECK-EXTEND-ROUND-NEXT:    uunpkhi z3.s, z0.h
-; CHECK-EXTEND-ROUND-NEXT:    uunpklo z0.s, z0.h
-; CHECK-EXTEND-ROUND-NEXT:    fcvt z2.h, p0/m, z2.s
-; CHECK-EXTEND-ROUND-NEXT:    fcvt z1.h, p0/m, z1.s
-; CHECK-EXTEND-ROUND-NEXT:    and z3.h, z3.h, #0x7fff
-; CHECK-EXTEND-ROUND-NEXT:    and z0.h, z0.h, #0x7fff
-; CHECK-EXTEND-ROUND-NEXT:    and z2.h, z2.h, #0x8000
-; CHECK-EXTEND-ROUND-NEXT:    and z1.h, z1.h, #0x8000
-; CHECK-EXTEND-ROUND-NEXT:    orr z2.d, z3.d, z2.d
-; CHECK-EXTEND-ROUND-NEXT:    orr z0.d, z0.d, z1.d
-; CHECK-EXTEND-ROUND-NEXT:    uzp1 z0.h, z0.h, z2.h
-; CHECK-EXTEND-ROUND-NEXT:    ret
+; CHECK-LABEL: test_copysign_v8f16_v8f32:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    ptrue p0.s
+; CHECK-NEXT:    and z0.h, z0.h, #0x7fff
+; CHECK-NEXT:    fcvt z2.h, p0/m, z2.s
+; CHECK-NEXT:    fcvt z1.h, p0/m, z1.s
+; CHECK-NEXT:    uzp1 z1.h, z1.h, z2.h
+; CHECK-NEXT:    and z1.h, z1.h, #0x8000
+; CHECK-NEXT:    orr z0.d, z0.d, z1.d
+; CHECK-NEXT:    ret
   %tmp0 = fptrunc <vscale x 8 x float> %b to <vscale x 8 x half>
   %r = call <vscale x 8 x half> @llvm.copysign.v8f16(<vscale x 8 x half> %a, <vscale x 8 x half> %tmp0)
   ret <vscale x 8 x half> %r
@@ -259,48 +210,28 @@ define <vscale x 8 x half> @test_copysign_v8f16_v8f32(<vscale x 8 x half> %a, <v
 ;========== FCOPYSIGN_EXTEND_ROUND
 
 define <vscale x 4 x half> @test_copysign_nxv4f32_nxv4f16(<vscale x 4 x float> %a, <vscale x 4 x float> %b) #0 {
-; CHECK-NO-EXTEND-ROUND-LABEL: test_copysign_nxv4f32_nxv4f16:
-; CHECK-NO-EXTEND-ROUND:       // %bb.0:
-; CHECK-NO-EXTEND-ROUND-NEXT:    and z1.s, z1.s, #0x80000000
-; CHECK-NO-EXTEND-ROUND-NEXT:    and z0.s, z0.s, #0x7fffffff
-; CHECK-NO-EXTEND-ROUND-NEXT:    ptrue p0.s
-; CHECK-NO-EXTEND-ROUND-NEXT:    orr z0.d, z0.d, z1.d
-; CHECK-NO-EXTEND-ROUND-NEXT:    fcvt z0.h, p0/m, z0.s
-; CHECK-NO-EXTEND-ROUND-NEXT:    ret
-;
-; CHECK-EXTEND-ROUND-LABEL: test_copysign_nxv4f32_nxv4f16:
-; CHECK-EXTEND-ROUND:       // %bb.0:
-; CHECK-EXTEND-ROUND-NEXT:    ptrue p0.s
-; CHECK-EXTEND-ROUND-NEXT:    fcvt z0.h, p0/m, z0.s
-; CHECK-EXTEND-ROUND-NEXT:    fcvt z1.h, p0/m, z1.s
-; CHECK-EXTEND-ROUND-NEXT:    and z1.h, z1.h, #0x8000
-; CHECK-EXTEND-ROUND-NEXT:    and z0.h, z0.h, #0x7fff
-; CHECK-EXTEND-ROUND-NEXT:    orr z0.d, z0.d, z1.d
-; CHECK-EXTEND-ROUND-NEXT:    ret
+; CHECK-LABEL: test_copysign_nxv4f32_nxv4f16:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    and z1.s, z1.s, #0x80000000
+; CHECK-NEXT:    and z0.s, z0.s, #0x7fffffff
+; CHECK-NEXT:    ptrue p0.s
+; CHECK-NEXT:    orr z0.d, z0.d, z1.d
+; CHECK-NEXT:    fcvt z0.h, p0/m, z0.s
+; CHECK-NEXT:    ret
   %t1 = call <vscale x 4 x float> @llvm.copysign.v4f32(<vscale x 4 x float> %a, <vscale x 4 x float> %b)
   %t2 = fptrunc <vscale x 4 x float> %t1 to <vscale x 4 x half>
   ret <vscale x 4 x half> %t2
 }
 
 define <vscale x 2 x float> @test_copysign_nxv2f64_nxv2f32(<vscale x 2 x double> %a, <vscale x 2 x double> %b) #0 {
-; CHECK-NO-EXTEND-ROUND-LABEL: test_copysign_nxv2f64_nxv2f32:
-; CHECK-NO-EXTEND-ROUND:       // %bb.0:
-; CHECK-NO-EXTEND-ROUND-NEXT:    and z1.d, z1.d, #0x8000000000000000
-; CHECK-NO-EXTEND-ROUND-NEXT:    and z0.d, z0.d, #0x7fffffffffffffff
-; CHECK-NO-EXTEND-ROUND-NEXT:    ptrue p0.d
-; CHECK-NO-EXTEND-ROUND-NEXT:    orr z0.d, z0.d, z1.d
-; CHECK-NO-EXTEND-ROUND-NEXT:    fcvt z0.s, p0/m, z0.d
-; CHECK-NO-EXTEND-ROUND-NEXT:    ret
-;
-; CHECK-EXTEND-ROUND-LABEL: test_copysign_nxv2f64_nxv2f32:
-; CHECK-EXTEND-ROUND:       // %bb.0:
-; CHECK-EXTEND-ROUND-NEXT:    ptrue p0.d
-; CHECK-EXTEND-ROUND-NEXT:    fcvt z0.s, p0/m, z0.d
-; CHECK-EXTEND-ROUND-NEXT:    fcvt z1.s, p0/m, z1.d
-; CHECK-EXTEND-ROUND-NEXT:    and z1.s, z1.s, #0x80000000
-; CHECK-EXTEND-ROUND-NEXT:    and z0.s, z0.s, #0x7fffffff
-; CHECK-EXTEND-ROUND-NEXT:    orr z0.d, z0.d, z1.d
-; CHECK-EXTEND-ROUND-NEXT:    ret
+; CHECK-LABEL: test_copysign_nxv2f64_nxv2f32:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    and z1.d, z1.d, #0x8000000000000000
+; CHECK-NEXT:    and z0.d, z0.d, #0x7fffffffffffffff
+; CHECK-NEXT:    ptrue p0.d
+; CHECK-NEXT:    orr z0.d, z0.d, z1.d
+; CHECK-NEXT:    fcvt z0.s, p0/m, z0.d
+; CHECK-NEXT:    ret
   %t1 = call <vscale x 2 x double> @llvm.copysign.v2f64(<vscale x 2 x double> %a, <vscale x 2 x double> %b)
   %t2 = fptrunc <vscale x 2 x double> %t1 to <vscale x 2 x float>
   ret <vscale x 2 x float> %t2

llvm/test/CodeGen/AArch64/sve-fixed-length-fcopysign.ll

@@ -1,10 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -aarch64-sve-vector-bits-min=256  < %s | FileCheck %s -check-prefixes=CHECK,VBITS_GE_256,CHECK_NO_EXTEND_ROUND
-; RUN: llc -aarch64-sve-vector-bits-min=512  < %s | FileCheck %s -check-prefixes=CHECK,VBITS_GE_512,CHECK_NO_EXTEND_ROUND
-; RUN: llc -aarch64-sve-vector-bits-min=2048 < %s | FileCheck %s -check-prefixes=CHECK,VBITS_GE_512,CHECK_NO_EXTEND_ROUND
-; RUN: llc -aarch64-sve-vector-bits-min=256  --combiner-vector-fcopysign-extend-round < %s | FileCheck %s -check-prefixes=CHECK,VBITS_GE_256,CHECK_EXTEND_ROUND
-; RUN: llc -aarch64-sve-vector-bits-min=512  --combiner-vector-fcopysign-extend-round < %s | FileCheck %s -check-prefixes=CHECK,VBITS_GE_512,CHECK_EXTEND_ROUND
-; RUN: llc -aarch64-sve-vector-bits-min=2048 --combiner-vector-fcopysign-extend-round < %s | FileCheck %s -check-prefixes=CHECK,VBITS_GE_512,CHECK_EXTEND_ROUND
+; RUN: llc -aarch64-sve-vector-bits-min=256  < %s | FileCheck %s -check-prefixes=CHECK,VBITS_GE_256
+; RUN: llc -aarch64-sve-vector-bits-min=512  < %s | FileCheck %s -check-prefixes=CHECK,VBITS_GE_512
+; RUN: llc -aarch64-sve-vector-bits-min=2048 < %s | FileCheck %s -check-prefixes=CHECK,VBITS_GE_512
 
 target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
 
@@ -436,30 +433,17 @@ define void @test_copysign_v2f64_v2f32(ptr %ap, ptr %bp) vscale_range(2,0) #0 {
 
 ; SplitVecRes mismatched
 define void @test_copysign_v4f64_v4f32(ptr %ap, ptr %bp) vscale_range(2,0) #0 {
-; CHECK_NO_EXTEND_ROUND-LABEL: test_copysign_v4f64_v4f32:
-; CHECK_NO_EXTEND_ROUND:       // %bb.0:
-; CHECK_NO_EXTEND_ROUND-NEXT:    ptrue p0.d, vl4
-; CHECK_NO_EXTEND_ROUND-NEXT:    ld1w { z0.d }, p0/z, [x1]
-; CHECK_NO_EXTEND_ROUND-NEXT:    ld1d { z1.d }, p0/z, [x0]
-; CHECK_NO_EXTEND_ROUND-NEXT:    fcvt z0.d, p0/m, z0.s
-; CHECK_NO_EXTEND_ROUND-NEXT:    and z1.d, z1.d, #0x7fffffffffffffff
-; CHECK_NO_EXTEND_ROUND-NEXT:    and z0.d, z0.d, #0x8000000000000000
-; CHECK_NO_EXTEND_ROUND-NEXT:    orr z0.d, z1.d, z0.d
-; CHECK_NO_EXTEND_ROUND-NEXT:    st1d { z0.d }, p0, [x0]
-; CHECK_NO_EXTEND_ROUND-NEXT:    ret
-;
-; CHECK_EXTEND_ROUND-LABEL: test_copysign_v4f64_v4f32:
-; CHECK_EXTEND_ROUND:       // %bb.0:
-; CHECK_EXTEND_ROUND-NEXT:    ldr q0, [x1]
-; CHECK_EXTEND_ROUND-NEXT:    ptrue p0.d, vl4
-; CHECK_EXTEND_ROUND-NEXT:    uunpklo z0.d, z0.s
-; CHECK_EXTEND_ROUND-NEXT:    ld1d { z1.d }, p0/z, [x0]
-; CHECK_EXTEND_ROUND-NEXT:    and z1.d, z1.d, #0x7fffffffffffffff
-; CHECK_EXTEND_ROUND-NEXT:    fcvt z0.d, p0/m, z0.s
-; CHECK_EXTEND_ROUND-NEXT:    and z0.d, z0.d, #0x8000000000000000
-; CHECK_EXTEND_ROUND-NEXT:    orr z0.d, z1.d, z0.d
-; CHECK_EXTEND_ROUND-NEXT:    st1d { z0.d }, p0, [x0]
-; CHECK_EXTEND_ROUND-NEXT:    ret
+; CHECK-LABEL: test_copysign_v4f64_v4f32:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    ptrue p0.d, vl4
+; CHECK-NEXT:    ld1w { z0.d }, p0/z, [x1]
+; CHECK-NEXT:    ld1d { z1.d }, p0/z, [x0]
+; CHECK-NEXT:    fcvt z0.d, p0/m, z0.s
+; CHECK-NEXT:    and z1.d, z1.d, #0x7fffffffffffffff
+; CHECK-NEXT:    and z0.d, z0.d, #0x8000000000000000
+; CHECK-NEXT:    orr z0.d, z1.d, z0.d
+; CHECK-NEXT:    st1d { z0.d }, p0, [x0]
+; CHECK-NEXT:    ret
   %a = load <4 x double>, ptr %ap
   %b = load <4 x float>, ptr %bp
   %tmp0 = fpext <4 x float> %b to <4 x double>