[AArch64] Remove UnsafeFPMath (#150876)

We should always use fast math flags, remove these global flags
incrementally.
See also
https://discourse.llvm.org/t/rfc-honor-pragmas-with-ffp-contract-fast/80797

Author: paperchalice

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

@@ -11325,7 +11325,7 @@ static SDValue emitFloatCompareMask(SDValue LHS, SDValue RHS, SDValue TVal,
 
 SDValue AArch64TargetLowering::LowerSELECT_CC(
     ISD::CondCode CC, SDValue LHS, SDValue RHS, SDValue TVal, SDValue FVal,
-    iterator_range<SDNode::user_iterator> Users, bool HasNoNaNs,
+    iterator_range<SDNode::user_iterator> Users, SDNodeFlags Flags,
     const SDLoc &DL, SelectionDAG &DAG) const {
   // Handle f128 first, because it will result in a comparison of some RTLIB
   // call result against zero.
@@ -11523,7 +11523,7 @@ SDValue AArch64TargetLowering::LowerSELECT_CC(
           return true;
         }
       })) {
-    bool NoNaNs = getTargetMachine().Options.NoNaNsFPMath || HasNoNaNs;
+    bool NoNaNs = getTargetMachine().Options.NoNaNsFPMath || Flags.hasNoNaNs();
     SDValue VectorCmp =
         emitFloatCompareMask(LHS, RHS, TVal, FVal, CC, NoNaNs, DL, DAG);
     if (VectorCmp)
@@ -11537,7 +11537,7 @@ SDValue AArch64TargetLowering::LowerSELECT_CC(
   AArch64CC::CondCode CC1, CC2;
   changeFPCCToAArch64CC(CC, CC1, CC2);
 
-  if (DAG.getTarget().Options.UnsafeFPMath) {
+  if (Flags.hasNoSignedZeros()) {
     // Transform "a == 0.0 ? 0.0 : x" to "a == 0.0 ? a : x" and
     // "a != 0.0 ? x : 0.0" to "a != 0.0 ? x : a" to avoid materializing 0.0.
     ConstantFPSDNode *RHSVal = dyn_cast<ConstantFPSDNode>(RHS);
@@ -11616,18 +11616,16 @@ SDValue AArch64TargetLowering::LowerSELECT_CC(SDValue Op,
   SDValue RHS = Op.getOperand(1);
   SDValue TVal = Op.getOperand(2);
   SDValue FVal = Op.getOperand(3);
-  bool HasNoNans = Op->getFlags().hasNoNaNs();
+  SDNodeFlags Flags = Op->getFlags();
   SDLoc DL(Op);
-  return LowerSELECT_CC(CC, LHS, RHS, TVal, FVal, Op->users(), HasNoNans, DL,
-                        DAG);
+  return LowerSELECT_CC(CC, LHS, RHS, TVal, FVal, Op->users(), Flags, DL, DAG);
 }
 
 SDValue AArch64TargetLowering::LowerSELECT(SDValue Op,
                                            SelectionDAG &DAG) const {
   SDValue CCVal = Op->getOperand(0);
   SDValue TVal = Op->getOperand(1);
   SDValue FVal = Op->getOperand(2);
-  bool HasNoNans = Op->getFlags().hasNoNaNs();
   SDLoc DL(Op);
 
   EVT Ty = Op.getValueType();
@@ -11694,8 +11692,8 @@ SDValue AArch64TargetLowering::LowerSELECT(SDValue Op,
                                      DAG.getUNDEF(MVT::f32), FVal);
   }
 
-  SDValue Res =
-      LowerSELECT_CC(CC, LHS, RHS, TVal, FVal, Op->users(), HasNoNans, DL, DAG);
+  SDValue Res = LowerSELECT_CC(CC, LHS, RHS, TVal, FVal, Op->users(),
+                               Op->getFlags(), DL, DAG);
 
   if ((Ty == MVT::f16 || Ty == MVT::bf16) && !Subtarget->hasFullFP16()) {
     return DAG.getTargetExtractSubreg(AArch64::hsub, DL, Ty, Res);
@@ -12292,7 +12290,9 @@ SDValue AArch64TargetLowering::getSqrtEstimate(SDValue Operand,
       SDLoc DL(Operand);
       EVT VT = Operand.getValueType();
 
-      SDNodeFlags Flags = SDNodeFlags::AllowReassociation;
+      // Ensure nodes can be recognized by isAssociativeAndCommutative.
+      SDNodeFlags Flags =
+          SDNodeFlags::AllowReassociation | SDNodeFlags::NoSignedZeros;
 
       // Newton reciprocal square root iteration: E * 0.5 * (3 - X * E^2)
       // AArch64 reciprocal square root iteration instruction: 0.5 * (3 - M * N)
@@ -16674,7 +16674,7 @@ bool AArch64TargetLowering::isProfitableToHoist(Instruction *I) const {
   return !(isFMAFasterThanFMulAndFAdd(*F, Ty) &&
            isOperationLegalOrCustom(ISD::FMA, getValueType(DL, Ty)) &&
            (Options.AllowFPOpFusion == FPOpFusion::Fast ||
-            Options.UnsafeFPMath));
+            I->getFastMathFlags().allowContract()));
 }
 
 // All 32-bit GPR operations implicitly zero the high-half of the corresponding

llvm/lib/Target/AArch64/AArch64ISelLowering.h

@@ -662,7 +662,7 @@ class AArch64TargetLowering : public TargetLowering {
   SDValue LowerSELECT_CC(ISD::CondCode CC, SDValue LHS, SDValue RHS,
                          SDValue TVal, SDValue FVal,
                          iterator_range<SDNode::user_iterator> Users,
-                         bool HasNoNans, const SDLoc &dl,
+                         SDNodeFlags Flags, const SDLoc &dl,
                          SelectionDAG &DAG) const;
   SDValue LowerINIT_TRAMPOLINE(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerADJUST_TRAMPOLINE(SDValue Op, SelectionDAG &DAG) const;

llvm/lib/Target/AArch64/AArch64InstrInfo.cpp

@@ -6574,10 +6574,8 @@ static bool isCombineInstrCandidateFP(const MachineInstr &Inst) {
     TargetOptions Options = Inst.getParent()->getParent()->getTarget().Options;
     // We can fuse FADD/FSUB with FMUL, if fusion is either allowed globally by
     // the target options or if FADD/FSUB has the contract fast-math flag.
-    return Options.UnsafeFPMath ||
-           Options.AllowFPOpFusion == FPOpFusion::Fast ||
+    return Options.AllowFPOpFusion == FPOpFusion::Fast ||
            Inst.getFlag(MachineInstr::FmContract);
-    return true;
   }
   return false;
 }
@@ -6680,9 +6678,8 @@ bool AArch64InstrInfo::isAssociativeAndCommutative(const MachineInstr &Inst,
   case AArch64::FMUL_ZZZ_H:
   case AArch64::FMUL_ZZZ_S:
   case AArch64::FMUL_ZZZ_D:
-    return Inst.getParent()->getParent()->getTarget().Options.UnsafeFPMath ||
-           (Inst.getFlag(MachineInstr::MIFlag::FmReassoc) &&
-            Inst.getFlag(MachineInstr::MIFlag::FmNsz));
+    return Inst.getFlag(MachineInstr::MIFlag::FmReassoc) &&
+           Inst.getFlag(MachineInstr::MIFlag::FmNsz);
 
   // == Integer types ==
   // -- Base instructions --

llvm/test/CodeGen/AArch64/aarch64-combine-fmul-fsub.mir

@@ -1,8 +1,8 @@
-# RUN: llc -run-pass=machine-combiner -o - -mtriple=aarch64-unknown-linux -mcpu=cortex-a57 -enable-unsafe-fp-math -machine-combiner-verify-pattern-order=true %s | FileCheck --check-prefixes=UNPROFITABLE,ALL %s
-# RUN: llc -run-pass=machine-combiner -o - -mtriple=aarch64-unknown-linux -mcpu=falkor -enable-unsafe-fp-math %s -machine-combiner-verify-pattern-order=true | FileCheck --check-prefixes=PROFITABLE,ALL %s
-# RUN: llc -run-pass=machine-combiner -o - -mtriple=aarch64-unknown-linux -mcpu=exynos-m3 -enable-unsafe-fp-math -machine-combiner-verify-pattern-order=true %s | FileCheck --check-prefixes=PROFITABLE,ALL %s
-# RUN: llc -run-pass=machine-combiner -o - -mtriple=aarch64-unknown-linux -mcpu=thunderx2t99 -enable-unsafe-fp-math -machine-combiner-verify-pattern-order=true %s | FileCheck --check-prefixes=PROFITABLE,ALL %s
-# RUN: llc -run-pass=machine-combiner -o - -mtriple=aarch64-unknown-linux -mcpu=thunderx3t110 -enable-unsafe-fp-math -machine-combiner-verify-pattern-order=true %s | FileCheck --check-prefixes=PROFITABLE,ALL %s
+# RUN: llc -run-pass=machine-combiner -o - -mtriple=aarch64-unknown-linux -mcpu=cortex-a57 -machine-combiner-verify-pattern-order=true %s | FileCheck --check-prefixes=UNPROFITABLE,ALL %s
+# RUN: llc -run-pass=machine-combiner -o - -mtriple=aarch64-unknown-linux -mcpu=falkor %s -machine-combiner-verify-pattern-order=true | FileCheck --check-prefixes=PROFITABLE,ALL %s
+# RUN: llc -run-pass=machine-combiner -o - -mtriple=aarch64-unknown-linux -mcpu=exynos-m3 -machine-combiner-verify-pattern-order=true %s | FileCheck --check-prefixes=PROFITABLE,ALL %s
+# RUN: llc -run-pass=machine-combiner -o - -mtriple=aarch64-unknown-linux -mcpu=thunderx2t99 -machine-combiner-verify-pattern-order=true %s | FileCheck --check-prefixes=PROFITABLE,ALL %s
+# RUN: llc -run-pass=machine-combiner -o - -mtriple=aarch64-unknown-linux -mcpu=thunderx3t110 -machine-combiner-verify-pattern-order=true %s | FileCheck --check-prefixes=PROFITABLE,ALL %s
 #
 name:            f1_2s
 registers:
@@ -16,18 +16,18 @@ body:             |
     %2:fpr64 = COPY $d2
     %1:fpr64 = COPY $d1
     %0:fpr64 = COPY $d0
-    %3:fpr64 = FMULv2f32 %0, %1, implicit $fpcr
-    %4:fpr64 = FSUBv2f32 killed %3, %2, implicit $fpcr
+    %3:fpr64 = contract FMULv2f32 %0, %1, implicit $fpcr
+    %4:fpr64 = contract FSUBv2f32 killed %3, %2, implicit $fpcr
     $d0 = COPY %4
     RET_ReallyLR implicit $d0
 
 ...
 # UNPROFITABLE-LABEL: name: f1_2s
-# UNPROFITABLE: [[R1:%[0-9]+]]:fpr64 = FNEGv2f32 %2
+# UNPROFITABLE: [[R1:%[0-9]+]]:fpr64 = contract FNEGv2f32 %2
 # UNPROFITABLE-NEXT: FMLAv2f32 killed [[R1]], %0, %1, implicit $fpcr
 #
 # PROFITABLE-LABEL: name: f1_2s
-# PROFITABLE: [[R1:%[0-9]+]]:fpr64 = FNEGv2f32 %2
+# PROFITABLE: [[R1:%[0-9]+]]:fpr64 = contract FNEGv2f32 %2
 # PROFITABLE-NEXT: FMLAv2f32 killed [[R1]], %0, %1, implicit $fpcr
 ---
 name:            f1_4s
@@ -42,18 +42,18 @@ body:             |
     %2:fpr128 = COPY $q2
     %1:fpr128 = COPY $q1
     %0:fpr128 = COPY $q0
-    %3:fpr128 = FMULv4f32 %0, %1, implicit $fpcr
-    %4:fpr128 = FSUBv4f32 killed %3, %2, implicit $fpcr
+    %3:fpr128 = contract FMULv4f32 %0, %1, implicit $fpcr
+    %4:fpr128 = contract FSUBv4f32 killed %3, %2, implicit $fpcr
     $q0 = COPY %4
     RET_ReallyLR implicit $q0
 
 ...
 # UNPROFITABLE-LABEL: name: f1_4s
-# UNPROFITABLE: [[R1:%[0-9]+]]:fpr128 = FMULv4f32 %0, %1, implicit $fpcr
+# UNPROFITABLE: [[R1:%[0-9]+]]:fpr128 = contract FMULv4f32 %0, %1, implicit $fpcr
 # UNPROFITABLE-NEXT: FSUBv4f32 killed [[R1]], %2, implicit $fpcr
 #
 # PROFITABLE-LABEL: name: f1_4s
-# PROFITABLE: [[R1:%[0-9]+]]:fpr128 = FNEGv4f32 %2
+# PROFITABLE: [[R1:%[0-9]+]]:fpr128 = contract FNEGv4f32 %2
 # PROFITABLE-NEXT: FMLAv4f32 killed [[R1]], %0, %1, implicit $fpcr
 ---
 name:            f1_2d
@@ -68,18 +68,18 @@ body:             |
     %2:fpr128 = COPY $q2
     %1:fpr128 = COPY $q1
     %0:fpr128 = COPY $q0
-    %3:fpr128 = FMULv2f64 %0, %1, implicit $fpcr
-    %4:fpr128 = FSUBv2f64 killed %3, %2, implicit $fpcr
+    %3:fpr128 = contract FMULv2f64 %0, %1, implicit $fpcr
+    %4:fpr128 = contract FSUBv2f64 killed %3, %2, implicit $fpcr
     $q0 = COPY %4
     RET_ReallyLR implicit $q0
 
 ...
 # UNPROFITABLE-LABEL: name: f1_2d
-# UNPROFITABLE: %3:fpr128 = FMULv2f64 %0, %1, implicit $fpcr
+# UNPROFITABLE: %3:fpr128 = contract FMULv2f64 %0, %1, implicit $fpcr
 # UNPROFITABLE-NEXT: FSUBv2f64 killed %3, %2, implicit $fpcr
 #
 # PROFITABLE-LABEL: name: f1_2d
-# PROFITABLE: [[R1:%[0-9]+]]:fpr128 = FNEGv2f64 %2
+# PROFITABLE: [[R1:%[0-9]+]]:fpr128 = contract FNEGv2f64 %2
 # PROFITABLE-NEXT: FMLAv2f64 killed [[R1]], %0, %1, implicit $fpcr
 ---
 name:            f1_both_fmul_2s
@@ -97,15 +97,15 @@ body:             |
     %2:fpr64 = COPY $q2
     %1:fpr64 = COPY $q1
     %0:fpr64 = COPY $q0
-    %4:fpr64 = FMULv2f32 %0, %1, implicit $fpcr
-    %5:fpr64 = FMULv2f32 %2, %3, implicit $fpcr
-    %6:fpr64 = FSUBv2f32 killed %4, %5, implicit $fpcr
+    %4:fpr64 = contract FMULv2f32 %0, %1, implicit $fpcr
+    %5:fpr64 = contract FMULv2f32 %2, %3, implicit $fpcr
+    %6:fpr64 = contract FSUBv2f32 killed %4, %5, implicit $fpcr
     $q0 = COPY %6
     RET_ReallyLR implicit $q0
 
 ...
 # ALL-LABEL: name: f1_both_fmul_2s
-# ALL: %4:fpr64 = FMULv2f32 %0, %1, implicit $fpcr
+# ALL: %4:fpr64 = contract FMULv2f32 %0, %1, implicit $fpcr
 # ALL-NEXT: FMLSv2f32 killed %4, %2, %3, implicit $fpcr
 ---
 name:            f1_both_fmul_4s
@@ -123,15 +123,15 @@ body:             |
     %2:fpr128 = COPY $q2
     %1:fpr128 = COPY $q1
     %0:fpr128 = COPY $q0
-    %4:fpr128 = FMULv4f32 %0, %1, implicit $fpcr
-    %5:fpr128 = FMULv4f32 %2, %3, implicit $fpcr
-    %6:fpr128 = FSUBv4f32 killed %4, %5, implicit $fpcr
+    %4:fpr128 = contract FMULv4f32 %0, %1, implicit $fpcr
+    %5:fpr128 = contract FMULv4f32 %2, %3, implicit $fpcr
+    %6:fpr128 = contract FSUBv4f32 killed %4, %5, implicit $fpcr
     $q0 = COPY %6
     RET_ReallyLR implicit $q0
 
 ...
 # ALL-LABEL: name: f1_both_fmul_4s
-# ALL: %4:fpr128 = FMULv4f32 %0, %1, implicit $fpcr
+# ALL: %4:fpr128 = contract FMULv4f32 %0, %1, implicit $fpcr
 # ALL-NEXT: FMLSv4f32 killed %4, %2, %3, implicit $fpcr
 ---
 name:            f1_both_fmul_2d
@@ -149,14 +149,14 @@ body:             |
     %2:fpr128 = COPY $q2
     %1:fpr128 = COPY $q1
     %0:fpr128 = COPY $q0
-    %4:fpr128 = FMULv2f64 %0, %1, implicit $fpcr
-    %5:fpr128 = FMULv2f64 %2, %3, implicit $fpcr
-    %6:fpr128 = FSUBv2f64 killed %4, %5, implicit $fpcr
+    %4:fpr128 = contract FMULv2f64 %0, %1, implicit $fpcr
+    %5:fpr128 = contract FMULv2f64 %2, %3, implicit $fpcr
+    %6:fpr128 = contract FSUBv2f64 killed %4, %5, implicit $fpcr
     $q0 = COPY %6
     RET_ReallyLR implicit $q0
 
 ...
 # ALL-LABEL: name: f1_both_fmul_2d
-# ALL: %4:fpr128 = FMULv2f64 %0, %1, implicit $fpcr
+# ALL: %4:fpr128 = contract FMULv2f64 %0, %1, implicit $fpcr
 # ALL-NEXT: FMLSv2f64 killed %4, %2, %3, implicit $fpcr
 

llvm/test/CodeGen/AArch64/arm64-fml-combines.ll

@@ -1,4 +1,4 @@
-; RUN: llc < %s -O3 -mtriple=arm64-apple-ios -enable-unsafe-fp-math -mattr=+fullfp16 | FileCheck %s
+; RUN: llc < %s -O3 -mtriple=arm64-apple-ios -mattr=+fullfp16 | FileCheck %s
 ; RUN: llc < %s -O3 -mtriple=arm64-apple-ios -fp-contract=fast -mattr=+fullfp16 | FileCheck %s
 
 define void @foo_2d(ptr %src) {
@@ -130,29 +130,29 @@ for.end:                                          ; preds = %for.body
 ; CHECK: fnmadd h0, h0, h1, h2
 define half @test0(half %a, half %b, half %c) {
 entry:
-  %0 = fmul half %a, %b
-  %mul = fsub half -0.000000e+00, %0
-  %sub1 = fsub half %mul, %c
+  %0 = fmul contract half %a, %b
+  %mul = fsub contract half -0.000000e+00, %0
+  %sub1 = fsub contract half %mul, %c
   ret half %sub1
 }
 
 ; CHECK-LABEL: test1:
 ; CHECK: fnmadd s0, s0, s1, s2
 define float @test1(float %a, float %b, float %c) {
 entry:
-  %0 = fmul float %a, %b
-  %mul = fsub float -0.000000e+00, %0
-  %sub1 = fsub float %mul, %c
+  %0 = fmul contract float %a, %b
+  %mul = fsub contract float -0.000000e+00, %0
+  %sub1 = fsub contract float %mul, %c
   ret float %sub1
 }
 
 ; CHECK-LABEL: test2:
 ; CHECK: fnmadd d0, d0, d1, d2
 define double @test2(double %a, double %b, double %c) {
 entry:
-  %0 = fmul double %a, %b
-  %mul = fsub double -0.000000e+00, %0
-  %sub1 = fsub double %mul, %c
+  %0 = fmul contract double %a, %b
+  %mul = fsub contract double -0.000000e+00, %0
+  %sub1 = fsub contract double %mul, %c
   ret double %sub1
 }
 

llvm/test/CodeGen/AArch64/fcsel-zero.ll

@@ -2,17 +2,17 @@
 
 ; RUN: llc -mtriple=aarch64-linux-gnu -o - < %s | FileCheck %s
 
-define float @foeq(float %a, float %b) #0 {
-  %t = fcmp oeq float %a, 0.0
+define float @foeq(float %a, float %b) {
+  %t = fcmp nsz oeq float %a, 0.0
   %v = select i1 %t, float 0.0, float %b
   ret float %v
 ; CHECK-LABEL: foeq
 ; CHECK: fcmp [[R:s[0-9]+]], #0.0
 ; CHECK-NEXT: fcsel {{s[0-9]+}}, [[R]], {{s[0-9]+}}, eq
 }
 
-define float @fueq(float %a, float %b) #0 {
-  %t = fcmp ueq float %a, 0.0
+define float @fueq(float %a, float %b) {
+  %t = fcmp nsz ueq float %a, 0.0
   %v = select i1 %t, float 0.0, float %b
   ret float %v
 ; CHECK-LABEL: fueq
@@ -21,8 +21,8 @@ define float @fueq(float %a, float %b) #0 {
 ; CHECK-NEXT: fcsel {{s[0-9]+}}, [[R]], {{s[0-9]+}}, vs
 }
 
-define float @fone(float %a, float %b) #0 {
-  %t = fcmp one float %a, 0.0
+define float @fone(float %a, float %b) {
+  %t = fcmp nsz one float %a, 0.0
   %v = select i1 %t, float %b, float 0.0
   ret float %v
 ; CHECK-LABEL: fone
@@ -31,26 +31,26 @@ define float @fone(float %a, float %b) #0 {
 ; CHECK-NEXT: fcsel {{s[0-9]+}}, {{s[0-9]+}}, [[R]], gt
 }
 
-define float @fune(float %a, float %b) #0 {
-  %t = fcmp une float %a, 0.0
+define float @fune(float %a, float %b) {
+  %t = fcmp nsz une float %a, 0.0
   %v = select i1 %t, float %b, float 0.0
   ret float %v
 ; CHECK-LABEL: fune
 ; CHECK: fcmp [[R:s[0-9]+]], #0.0
 ; CHECK-NEXT: fcsel {{s[0-9]+}}, {{s[0-9]+}}, [[R]], ne
 }
 
-define double @doeq(double %a, double %b) #0 {
-  %t = fcmp oeq double %a, 0.0
+define double @doeq(double %a, double %b) {
+  %t = fcmp nsz oeq double %a, 0.0
   %v = select i1 %t, double 0.0, double %b
   ret double %v
 ; CHECK-LABEL: doeq
 ; CHECK: fcmp [[R:d[0-9]+]], #0.0
 ; CHECK-NEXT: fcsel {{d[0-9]+}}, [[R]], {{d[0-9]+}}, eq
 }
 
-define double @dueq(double %a, double %b) #0 {
-  %t = fcmp ueq double %a, 0.0
+define double @dueq(double %a, double %b) {
+  %t = fcmp nsz ueq double %a, 0.0
   %v = select i1 %t, double 0.0, double %b
   ret double %v
 ; CHECK-LABEL: dueq
@@ -59,8 +59,8 @@ define double @dueq(double %a, double %b) #0 {
 ; CHECK-NEXT: fcsel {{d[0-9]+}}, [[R]], {{d[0-9]+}}, vs
 }
 
-define double @done(double %a, double %b) #0 {
-  %t = fcmp one double %a, 0.0
+define double @done(double %a, double %b) {
+  %t = fcmp nsz one double %a, 0.0
   %v = select i1 %t, double %b, double 0.0
   ret double %v
 ; CHECK-LABEL: done
@@ -69,14 +69,11 @@ define double @done(double %a, double %b) #0 {
 ; CHECK-NEXT: fcsel {{d[0-9]+}}, {{d[0-9]+}}, [[R]], gt
 }
 
-define double @dune(double %a, double %b) #0 {
-  %t = fcmp une double %a, 0.0
+define double @dune(double %a, double %b) {
+  %t = fcmp nsz une double %a, 0.0
   %v = select i1 %t, double %b, double 0.0
   ret double %v
 ; CHECK-LABEL: dune
 ; CHECK: fcmp [[R:d[0-9]+]], #0.0
 ; CHECK-NEXT: fcsel {{d[0-9]+}}, {{d[0-9]+}}, [[R]], ne
 }
-
-attributes #0 = { nounwind "unsafe-fp-math"="true" }
-