[llvm] r354298 - [CGP] form usub with overflow from sub+icmp

Teresa Johnson via llvm-commits llvm-commits at lists.llvm.org
Wed Mar 13 21:54:31 PDT 2019


Hi Sanjay,

Unfortunately we are having some additional problems with this patch. One
is a compiler assertion (which goes away after r355823 although since that
patch just added a heuristic guard on the transformation it is likely just
hidden). I filed https://bugs.llvm.org/show_bug.cgi?id=41064 for that one.

The other is a performance slowdown. Carrot who is copied here can send you
more info about that.

Thanks,
Teresa

On Mon, Feb 18, 2019 at 3:32 PM Sanjay Patel via llvm-commits <
llvm-commits at lists.llvm.org> wrote:

> Author: spatel
> Date: Mon Feb 18 15:33:05 2019
> New Revision: 354298
>
> URL: http://llvm.org/viewvc/llvm-project?rev=354298&view=rev
> Log:
> [CGP] form usub with overflow from sub+icmp
>
> The motivating x86 cases for forming the intrinsic are shown in PR31754
> and PR40487:
> https://bugs.llvm.org/show_bug.cgi?id=31754
> https://bugs.llvm.org/show_bug.cgi?id=40487
> ..and those are shown in the IR test file and x86 codegen file.
>
> Matching the usubo pattern is harder than uaddo because we have 2
> independent values rather than a def-use.
>
> This adds a TLI hook that should preserve the existing behavior for uaddo
> formation, but disables usubo
> formation by default. Only x86 overrides that setting for now although
> other targets will likely benefit
> by forming usbuo too.
>
> Differential Revision: https://reviews.llvm.org/D57789
>
> Modified:
>     llvm/trunk/include/llvm/CodeGen/TargetLowering.h
>     llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp
>     llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
>     llvm/trunk/lib/Target/X86/X86ISelLowering.h
>     llvm/trunk/test/CodeGen/X86/cgp-usubo.ll
>     llvm/trunk/test/CodeGen/X86/lsr-loop-exit-cond.ll
>     llvm/trunk/test/Transforms/CodeGenPrepare/X86/overflow-intrinsics.ll
>
> Modified: llvm/trunk/include/llvm/CodeGen/TargetLowering.h
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/TargetLowering.h?rev=354298&r1=354297&r2=354298&view=diff
>
> ==============================================================================
> --- llvm/trunk/include/llvm/CodeGen/TargetLowering.h (original)
> +++ llvm/trunk/include/llvm/CodeGen/TargetLowering.h Mon Feb 18 15:33:05
> 2019
> @@ -2439,6 +2439,23 @@ public:
>      return false;
>    }
>
> +  /// Try to convert math with an overflow comparison into the
> corresponding DAG
> +  /// node operation. Targets may want to override this independently of
> whether
> +  /// the operation is legal/custom for the given type because it may
> obscure
> +  /// matching of other patterns.
> +  virtual bool shouldFormOverflowOp(unsigned Opcode, EVT VT) const {
> +    // TODO: The default logic is inherited from code in CodeGenPrepare.
> +    // The opcode should not make a difference by default?
> +    if (Opcode != ISD::UADDO)
> +      return false;
> +
> +    // Allow the transform as long as we have an integer type that is not
> +    // obviously illegal and unsupported.
> +    if (VT.isVector())
> +      return false;
> +    return VT.isSimple() || !isOperationExpand(Opcode, VT);
> +  }
> +
>    // Return true if it is profitable to use a scalar input to a
> BUILD_VECTOR
>    // even if the vector itself has multiple uses.
>    virtual bool aggressivelyPreferBuildVectorSources(EVT VecVT) const {
>
> Modified: llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp?rev=354298&r1=354297&r2=354298&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp (original)
> +++ llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp Mon Feb 18 15:33:05 2019
> @@ -1162,9 +1162,18 @@ static bool OptimizeNoopCopyExpression(C
>  static void replaceMathCmpWithIntrinsic(BinaryOperator *BO, CmpInst *Cmp,
>                                          Instruction *InsertPt,
>                                          Intrinsic::ID IID) {
> +  Value *Arg0 = BO->getOperand(0);
> +  Value *Arg1 = BO->getOperand(1);
> +
> +  // We allow matching the canonical IR (add X, C) back to (usubo X, -C).
> +  if (BO->getOpcode() == Instruction::Add &&
> +      IID == Intrinsic::usub_with_overflow) {
> +    assert(isa<Constant>(Arg1) && "Unexpected input for usubo");
> +    Arg1 = ConstantExpr::getNeg(cast<Constant>(Arg1));
> +  }
> +
>    IRBuilder<> Builder(InsertPt);
> -  Value *MathOV = Builder.CreateBinaryIntrinsic(IID, BO->getOperand(0),
> -                                                BO->getOperand(1));
> +  Value *MathOV = Builder.CreateBinaryIntrinsic(IID, Arg0, Arg1);
>    Value *Math = Builder.CreateExtractValue(MathOV, 0, "math");
>    Value *OV = Builder.CreateExtractValue(MathOV, 1, "ov");
>    BO->replaceAllUsesWith(Math);
> @@ -1182,13 +1191,8 @@ static bool combineToUAddWithOverflow(Cm
>    if (!match(Cmp, m_UAddWithOverflow(m_Value(A), m_Value(B),
> m_BinOp(Add))))
>      return false;
>
> -  // Allow the transform as long as we have an integer type that is not
> -  // obviously illegal and unsupported.
> -  Type *Ty = Add->getType();
> -  if (!isa<IntegerType>(Ty))
> -    return false;
> -  EVT CodegenVT = TLI.getValueType(DL, Ty);
> -  if (!CodegenVT.isSimple() && TLI.isOperationExpand(ISD::UADDO,
> CodegenVT))
> +  if (!TLI.shouldFormOverflowOp(ISD::UADDO,
> +                                TLI.getValueType(DL, Add->getType())))
>      return false;
>
>    // We don't want to move around uses of condition values this late, so
> we
> @@ -1210,6 +1214,64 @@ static bool combineToUAddWithOverflow(Cm
>    return true;
>  }
>
> +static bool combineToUSubWithOverflow(CmpInst *Cmp, const TargetLowering
> &TLI,
> +                                      const DataLayout &DL, bool
> &ModifiedDT) {
> +  // Convert (A u> B) to (A u< B) to simplify pattern matching.
> +  Value *A = Cmp->getOperand(0), *B = Cmp->getOperand(1);
> +  ICmpInst::Predicate Pred = Cmp->getPredicate();
> +  if (Pred == ICmpInst::ICMP_UGT) {
> +    std::swap(A, B);
> +    Pred = ICmpInst::ICMP_ULT;
> +  }
> +  // Convert special-case: (A == 0) is the same as (A u< 1).
> +  if (Pred == ICmpInst::ICMP_EQ && match(B, m_ZeroInt())) {
> +    B = ConstantInt::get(B->getType(), 1);
> +    Pred = ICmpInst::ICMP_ULT;
> +  }
> +  if (Pred != ICmpInst::ICMP_ULT)
> +    return false;
> +
> +  // Walk the users of a variable operand of a compare looking for a
> subtract or
> +  // add with that same operand. Also match the 2nd operand of the
> compare to
> +  // the add/sub, but that may be a negated constant operand of an add.
> +  Value *CmpVariableOperand = isa<Constant>(A) ? B : A;
> +  BinaryOperator *Sub = nullptr;
> +  for (User *U : CmpVariableOperand->users()) {
> +    // A - B, A u< B --> usubo(A, B)
> +    if (match(U, m_Sub(m_Specific(A), m_Specific(B)))) {
> +      Sub = cast<BinaryOperator>(U);
> +      break;
> +    }
> +
> +    // A + (-C), A u< C (canonicalized form of (sub A, C))
> +    const APInt *CmpC, *AddC;
> +    if (match(U, m_Add(m_Specific(A), m_APInt(AddC))) &&
> +        match(B, m_APInt(CmpC)) && *AddC == -(*CmpC)) {
> +      Sub = cast<BinaryOperator>(U);
> +      break;
> +    }
> +  }
> +  if (!Sub)
> +    return false;
> +
> +  if (!TLI.shouldFormOverflowOp(ISD::USUBO,
> +                                TLI.getValueType(DL, Sub->getType())))
> +    return false;
> +
> +  // Pattern matched and profitability checked. Check dominance to
> determine the
> +  // insertion point for an intrinsic that replaces the subtract and
> compare.
> +  DominatorTree DT(*Sub->getFunction());
> +  bool SubDominates = DT.dominates(Sub, Cmp);
> +  if (!SubDominates && !DT.dominates(Cmp, Sub))
> +    return false;
> +  Instruction *InPt = SubDominates ? cast<Instruction>(Sub)
> +                                   : cast<Instruction>(Cmp);
> +  replaceMathCmpWithIntrinsic(Sub, Cmp, InPt,
> Intrinsic::usub_with_overflow);
> +  // Reset callers - do not crash by iterating over a dead instruction.
> +  ModifiedDT = true;
> +  return true;
> +}
> +
>  /// Sink the given CmpInst into user blocks to reduce the number of
> virtual
>  /// registers that must be created and coalesced. This is a clear win
> except on
>  /// targets with multiple condition code registers (PowerPC), where it
> might
> @@ -1276,14 +1338,17 @@ static bool sinkCmpExpression(CmpInst *C
>    return MadeChange;
>  }
>
> -static bool optimizeCmpExpression(CmpInst *Cmp, const TargetLowering &TLI,
> -                                  const DataLayout &DL) {
> +static bool optimizeCmp(CmpInst *Cmp, const TargetLowering &TLI,
> +                        const DataLayout &DL, bool &ModifiedDT) {
>    if (sinkCmpExpression(Cmp, TLI))
>      return true;
>
>    if (combineToUAddWithOverflow(Cmp, TLI, DL))
>      return true;
>
> +  if (combineToUSubWithOverflow(Cmp, TLI, DL, ModifiedDT))
> +    return true;
> +
>    return false;
>  }
>
> @@ -6770,8 +6835,8 @@ bool CodeGenPrepare::optimizeInst(Instru
>      return false;
>    }
>
> -  if (CmpInst *CI = dyn_cast<CmpInst>(I))
> -    if (TLI && optimizeCmpExpression(CI, *TLI, *DL))
> +  if (auto *Cmp = dyn_cast<CmpInst>(I))
> +    if (TLI && optimizeCmp(Cmp, *TLI, *DL, ModifiedDT))
>        return true;
>
>    if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
>
> Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=354298&r1=354297&r2=354298&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
> +++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Mon Feb 18 15:33:05 2019
> @@ -4934,6 +4934,13 @@ bool X86TargetLowering::shouldScalarizeB
>    return isOperationLegalOrCustomOrPromote(VecOp.getOpcode(), ScalarVT);
>  }
>
> +bool X86TargetLowering::shouldFormOverflowOp(unsigned Opcode, EVT VT)
> const {
> +  // TODO: Allow vectors?
> +  if (VT.isVector())
> +    return false;
> +  return VT.isSimple() || !isOperationExpand(Opcode, VT);
> +}
> +
>  bool X86TargetLowering::isCheapToSpeculateCttz() const {
>    // Speculate cttz only if we can directly use TZCNT.
>    return Subtarget.hasBMI();
>
> Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.h
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.h?rev=354298&r1=354297&r2=354298&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/Target/X86/X86ISelLowering.h (original)
> +++ llvm/trunk/lib/Target/X86/X86ISelLowering.h Mon Feb 18 15:33:05 2019
> @@ -1071,6 +1071,11 @@ namespace llvm {
>      /// supported.
>      bool shouldScalarizeBinop(SDValue) const override;
>
> +    /// Overflow nodes should get combined/lowered to optimal instructions
> +    /// (they should allow eliminating explicit compares by getting flags
> from
> +    /// math ops).
> +    bool shouldFormOverflowOp(unsigned Opcode, EVT VT) const override;
> +
>      bool storeOfVectorConstantIsCheap(EVT MemVT, unsigned NumElem,
>                                        unsigned AddrSpace) const override {
>        // If we can replace more than 2 scalar stores, there will be a
> reduction
>
> Modified: llvm/trunk/test/CodeGen/X86/cgp-usubo.ll
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/cgp-usubo.ll?rev=354298&r1=354297&r2=354298&view=diff
>
> ==============================================================================
> --- llvm/trunk/test/CodeGen/X86/cgp-usubo.ll (original)
> +++ llvm/trunk/test/CodeGen/X86/cgp-usubo.ll Mon Feb 18 15:33:05 2019
> @@ -7,8 +7,8 @@ define i1 @usubo_ult_i64(i64 %x, i64 %y,
>  ; CHECK-LABEL: usubo_ult_i64:
>  ; CHECK:       # %bb.0:
>  ; CHECK-NEXT:    subq %rsi, %rdi
> -; CHECK-NEXT:    movq %rdi, (%rdx)
>  ; CHECK-NEXT:    setb %al
> +; CHECK-NEXT:    movq %rdi, (%rdx)
>  ; CHECK-NEXT:    retq
>    %s = sub i64 %x, %y
>    store i64 %s, i64* %p
> @@ -21,9 +21,8 @@ define i1 @usubo_ult_i64(i64 %x, i64 %y,
>  define i1 @usubo_ugt_i32(i32 %x, i32 %y, i32* %p) nounwind {
>  ; CHECK-LABEL: usubo_ugt_i32:
>  ; CHECK:       # %bb.0:
> -; CHECK-NEXT:    cmpl %edi, %esi
> -; CHECK-NEXT:    seta %al
>  ; CHECK-NEXT:    subl %esi, %edi
> +; CHECK-NEXT:    setb %al
>  ; CHECK-NEXT:    movl %edi, (%rdx)
>  ; CHECK-NEXT:    retq
>    %ov = icmp ugt i32 %y, %x
> @@ -39,8 +38,7 @@ define i1 @usubo_ugt_constant_op0_i8(i8
>  ; CHECK:       # %bb.0:
>  ; CHECK-NEXT:    movb $42, %cl
>  ; CHECK-NEXT:    subb %dil, %cl
> -; CHECK-NEXT:    cmpb $42, %dil
> -; CHECK-NEXT:    seta %al
> +; CHECK-NEXT:    setb %al
>  ; CHECK-NEXT:    movb %cl, (%rsi)
>  ; CHECK-NEXT:    retq
>    %s = sub i8 42, %x
> @@ -54,10 +52,9 @@ define i1 @usubo_ugt_constant_op0_i8(i8
>  define i1 @usubo_ult_constant_op0_i16(i16 %x, i16* %p) nounwind {
>  ; CHECK-LABEL: usubo_ult_constant_op0_i16:
>  ; CHECK:       # %bb.0:
> -; CHECK-NEXT:    movl $43, %ecx
> -; CHECK-NEXT:    subl %edi, %ecx
> -; CHECK-NEXT:    cmpw $43, %di
> -; CHECK-NEXT:    seta %al
> +; CHECK-NEXT:    movw $43, %cx
> +; CHECK-NEXT:    subw %di, %cx
> +; CHECK-NEXT:    setb %al
>  ; CHECK-NEXT:    movw %cx, (%rsi)
>  ; CHECK-NEXT:    retq
>    %s = sub i16 43, %x
> @@ -71,11 +68,9 @@ define i1 @usubo_ult_constant_op0_i16(i1
>  define i1 @usubo_ult_constant_op1_i16(i16 %x, i16* %p) nounwind {
>  ; CHECK-LABEL: usubo_ult_constant_op1_i16:
>  ; CHECK:       # %bb.0:
> -; CHECK-NEXT:    movl %edi, %ecx
> -; CHECK-NEXT:    addl $-44, %ecx
> -; CHECK-NEXT:    cmpw $44, %di
> +; CHECK-NEXT:    subw $44, %di
>  ; CHECK-NEXT:    setb %al
> -; CHECK-NEXT:    movw %cx, (%rsi)
> +; CHECK-NEXT:    movw %di, (%rsi)
>  ; CHECK-NEXT:    retq
>    %s = add i16 %x, -44
>    %ov = icmp ult i16 %x, 44
> @@ -86,9 +81,8 @@ define i1 @usubo_ult_constant_op1_i16(i1
>  define i1 @usubo_ugt_constant_op1_i8(i8 %x, i8* %p) nounwind {
>  ; CHECK-LABEL: usubo_ugt_constant_op1_i8:
>  ; CHECK:       # %bb.0:
> -; CHECK-NEXT:    cmpb $45, %dil
> +; CHECK-NEXT:    subb $45, %dil
>  ; CHECK-NEXT:    setb %al
> -; CHECK-NEXT:    addb $-45, %dil
>  ; CHECK-NEXT:    movb %dil, (%rsi)
>  ; CHECK-NEXT:    retq
>    %ov = icmp ugt i8 45, %x
> @@ -102,11 +96,9 @@ define i1 @usubo_ugt_constant_op1_i8(i8
>  define i1 @usubo_eq_constant1_op1_i32(i32 %x, i32* %p) nounwind {
>  ; CHECK-LABEL: usubo_eq_constant1_op1_i32:
>  ; CHECK:       # %bb.0:
> -; CHECK-NEXT:    # kill: def $edi killed $edi def $rdi
> -; CHECK-NEXT:    leal -1(%rdi), %ecx
> -; CHECK-NEXT:    testl %edi, %edi
> -; CHECK-NEXT:    sete %al
> -; CHECK-NEXT:    movl %ecx, (%rsi)
> +; CHECK-NEXT:    subl $1, %edi
> +; CHECK-NEXT:    setb %al
> +; CHECK-NEXT:    movl %edi, (%rsi)
>  ; CHECK-NEXT:    retq
>    %s = add i32 %x, -1
>    %ov = icmp eq i32 %x, 0
> @@ -124,17 +116,14 @@ define i1 @usubo_ult_sub_dominates_i64(i
>  ; CHECK-NEXT:    testb $1, %cl
>  ; CHECK-NEXT:    je .LBB7_2
>  ; CHECK-NEXT:  # %bb.1: # %t
> -; CHECK-NEXT:    movq %rdi, %rax
> -; CHECK-NEXT:    subq %rsi, %rax
> -; CHECK-NEXT:    movq %rax, (%rdx)
> -; CHECK-NEXT:    testb $1, %cl
> -; CHECK-NEXT:    je .LBB7_2
> -; CHECK-NEXT:  # %bb.3: # %end
> -; CHECK-NEXT:    cmpq %rsi, %rdi
> +; CHECK-NEXT:    subq %rsi, %rdi
>  ; CHECK-NEXT:    setb %al
> -; CHECK-NEXT:    retq
> +; CHECK-NEXT:    movq %rdi, (%rdx)
> +; CHECK-NEXT:    testb $1, %cl
> +; CHECK-NEXT:    jne .LBB7_3
>  ; CHECK-NEXT:  .LBB7_2: # %f
>  ; CHECK-NEXT:    movl %ecx, %eax
> +; CHECK-NEXT:  .LBB7_3: # %end
>  ; CHECK-NEXT:    retq
>  entry:
>    br i1 %cond, label %t, label %f
>
> Modified: llvm/trunk/test/CodeGen/X86/lsr-loop-exit-cond.ll
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/lsr-loop-exit-cond.ll?rev=354298&r1=354297&r2=354298&view=diff
>
> ==============================================================================
> --- llvm/trunk/test/CodeGen/X86/lsr-loop-exit-cond.ll (original)
> +++ llvm/trunk/test/CodeGen/X86/lsr-loop-exit-cond.ll Mon Feb 18 15:33:05
> 2019
> @@ -16,11 +16,11 @@ define void @t(i8* nocapture %in, i8* no
>  ; GENERIC-NEXT:    movl (%rdx), %eax
>  ; GENERIC-NEXT:    movl 4(%rdx), %ebx
>  ; GENERIC-NEXT:    decl %ecx
> -; GENERIC-NEXT:    leaq 20(%rdx), %r14
> +; GENERIC-NEXT:    leaq 20(%rdx), %r11
>  ; GENERIC-NEXT:    movq _Te0@{{.*}}(%rip), %r9
>  ; GENERIC-NEXT:    movq _Te1@{{.*}}(%rip), %r8
>  ; GENERIC-NEXT:    movq _Te3@{{.*}}(%rip), %r10
> -; GENERIC-NEXT:    movq %rcx, %r11
> +; GENERIC-NEXT:    movq %rcx, %r14
>  ; GENERIC-NEXT:    jmp LBB0_1
>  ; GENERIC-NEXT:    .p2align 4, 0x90
>  ; GENERIC-NEXT:  LBB0_2: ## %bb1
> @@ -29,14 +29,13 @@ define void @t(i8* nocapture %in, i8* no
>  ; GENERIC-NEXT:    shrl $16, %ebx
>  ; GENERIC-NEXT:    movzbl %bl, %ebx
>  ; GENERIC-NEXT:    xorl (%r8,%rbx,4), %eax
> -; GENERIC-NEXT:    xorl -4(%r14), %eax
> +; GENERIC-NEXT:    xorl -4(%r11), %eax
>  ; GENERIC-NEXT:    shrl $24, %edi
>  ; GENERIC-NEXT:    movzbl %bpl, %ebx
>  ; GENERIC-NEXT:    movl (%r10,%rbx,4), %ebx
>  ; GENERIC-NEXT:    xorl (%r9,%rdi,4), %ebx
> -; GENERIC-NEXT:    xorl (%r14), %ebx
> -; GENERIC-NEXT:    decq %r11
> -; GENERIC-NEXT:    addq $16, %r14
> +; GENERIC-NEXT:    xorl (%r11), %ebx
> +; GENERIC-NEXT:    addq $16, %r11
>  ; GENERIC-NEXT:  LBB0_1: ## %bb
>  ; GENERIC-NEXT:    ## =>This Inner Loop Header: Depth=1
>  ; GENERIC-NEXT:    movzbl %al, %edi
> @@ -47,16 +46,16 @@ define void @t(i8* nocapture %in, i8* no
>  ; GENERIC-NEXT:    movzbl %bpl, %ebp
>  ; GENERIC-NEXT:    movl (%r8,%rbp,4), %ebp
>  ; GENERIC-NEXT:    xorl (%r9,%rax,4), %ebp
> -; GENERIC-NEXT:    xorl -12(%r14), %ebp
> +; GENERIC-NEXT:    xorl -12(%r11), %ebp
>  ; GENERIC-NEXT:    shrl $24, %ebx
>  ; GENERIC-NEXT:    movl (%r10,%rdi,4), %edi
>  ; GENERIC-NEXT:    xorl (%r9,%rbx,4), %edi
> -; GENERIC-NEXT:    xorl -8(%r14), %edi
> +; GENERIC-NEXT:    xorl -8(%r11), %edi
>  ; GENERIC-NEXT:    movl %ebp, %eax
>  ; GENERIC-NEXT:    shrl $24, %eax
>  ; GENERIC-NEXT:    movl (%r9,%rax,4), %eax
> -; GENERIC-NEXT:    testq %r11, %r11
> -; GENERIC-NEXT:    jne LBB0_2
> +; GENERIC-NEXT:    subq $1, %r14
> +; GENERIC-NEXT:    jae LBB0_2
>  ; GENERIC-NEXT:  ## %bb.3: ## %bb2
>  ; GENERIC-NEXT:    shlq $4, %rcx
>  ; GENERIC-NEXT:    andl $-16777216, %eax ## imm = 0xFF000000
> @@ -99,27 +98,26 @@ define void @t(i8* nocapture %in, i8* no
>  ; ATOM-NEXT:    ## kill: def $ecx killed $ecx def $rcx
>  ; ATOM-NEXT:    movl (%rdx), %r15d
>  ; ATOM-NEXT:    movl 4(%rdx), %eax
> -; ATOM-NEXT:    leaq 20(%rdx), %r14
> +; ATOM-NEXT:    leaq 20(%rdx), %r11
>  ; ATOM-NEXT:    movq _Te0@{{.*}}(%rip), %r9
>  ; ATOM-NEXT:    movq _Te1@{{.*}}(%rip), %r8
>  ; ATOM-NEXT:    movq _Te3@{{.*}}(%rip), %r10
>  ; ATOM-NEXT:    decl %ecx
> -; ATOM-NEXT:    movq %rcx, %r11
> +; ATOM-NEXT:    movq %rcx, %r14
>  ; ATOM-NEXT:    jmp LBB0_1
>  ; ATOM-NEXT:    .p2align 4, 0x90
>  ; ATOM-NEXT:  LBB0_2: ## %bb1
>  ; ATOM-NEXT:    ## in Loop: Header=BB0_1 Depth=1
>  ; ATOM-NEXT:    shrl $16, %eax
>  ; ATOM-NEXT:    shrl $24, %edi
> -; ATOM-NEXT:    decq %r11
> -; ATOM-NEXT:    movzbl %al, %ebp
> +; ATOM-NEXT:    movzbl %al, %eax
> +; ATOM-NEXT:    xorl (%r8,%rax,4), %r15d
>  ; ATOM-NEXT:    movzbl %bl, %eax
>  ; ATOM-NEXT:    movl (%r10,%rax,4), %eax
> -; ATOM-NEXT:    xorl (%r8,%rbp,4), %r15d
> +; ATOM-NEXT:    xorl -4(%r11), %r15d
>  ; ATOM-NEXT:    xorl (%r9,%rdi,4), %eax
> -; ATOM-NEXT:    xorl -4(%r14), %r15d
> -; ATOM-NEXT:    xorl (%r14), %eax
> -; ATOM-NEXT:    addq $16, %r14
> +; ATOM-NEXT:    xorl (%r11), %eax
> +; ATOM-NEXT:    addq $16, %r11
>  ; ATOM-NEXT:  LBB0_1: ## %bb
>  ; ATOM-NEXT:    ## =>This Inner Loop Header: Depth=1
>  ; ATOM-NEXT:    movl %eax, %edi
> @@ -132,15 +130,15 @@ define void @t(i8* nocapture %in, i8* no
>  ; ATOM-NEXT:    movzbl %r15b, %edi
>  ; ATOM-NEXT:    xorl (%r9,%rbp,4), %ebx
>  ; ATOM-NEXT:    movl (%r10,%rdi,4), %edi
> -; ATOM-NEXT:    xorl -12(%r14), %ebx
> +; ATOM-NEXT:    xorl -12(%r11), %ebx
>  ; ATOM-NEXT:    xorl (%r9,%rax,4), %edi
>  ; ATOM-NEXT:    movl %ebx, %eax
> -; ATOM-NEXT:    xorl -8(%r14), %edi
> +; ATOM-NEXT:    xorl -8(%r11), %edi
>  ; ATOM-NEXT:    shrl $24, %eax
>  ; ATOM-NEXT:    movl (%r9,%rax,4), %r15d
> -; ATOM-NEXT:    testq %r11, %r11
> +; ATOM-NEXT:    subq $1, %r14
>  ; ATOM-NEXT:    movl %edi, %eax
> -; ATOM-NEXT:    jne LBB0_2
> +; ATOM-NEXT:    jae LBB0_2
>  ; ATOM-NEXT:  ## %bb.3: ## %bb2
>  ; ATOM-NEXT:    shrl $16, %eax
>  ; ATOM-NEXT:    shrl $8, %edi
>
> Modified:
> llvm/trunk/test/Transforms/CodeGenPrepare/X86/overflow-intrinsics.ll
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/CodeGenPrepare/X86/overflow-intrinsics.ll?rev=354298&r1=354297&r2=354298&view=diff
>
> ==============================================================================
> --- llvm/trunk/test/Transforms/CodeGenPrepare/X86/overflow-intrinsics.ll
> (original)
> +++ llvm/trunk/test/Transforms/CodeGenPrepare/X86/overflow-intrinsics.ll
> Mon Feb 18 15:33:05 2019
> @@ -175,10 +175,11 @@ define i1 @uaddo_i42_increment_illegal_t
>
>  define i1 @usubo_ult_i64(i64 %x, i64 %y, i64* %p) {
>  ; CHECK-LABEL: @usubo_ult_i64(
> -; CHECK-NEXT:    [[S:%.*]] = sub i64 [[X:%.*]], [[Y:%.*]]
> -; CHECK-NEXT:    store i64 [[S]], i64* [[P:%.*]]
> -; CHECK-NEXT:    [[OV:%.*]] = icmp ult i64 [[X]], [[Y]]
> -; CHECK-NEXT:    ret i1 [[OV]]
> +; CHECK-NEXT:    [[TMP1:%.*]] = call { i64, i1 }
> @llvm.usub.with.overflow.i64(i64 [[X:%.*]], i64 [[Y:%.*]])
> +; CHECK-NEXT:    [[MATH:%.*]] = extractvalue { i64, i1 } [[TMP1]], 0
> +; CHECK-NEXT:    [[OV1:%.*]] = extractvalue { i64, i1 } [[TMP1]], 1
> +; CHECK-NEXT:    store i64 [[MATH]], i64* [[P:%.*]]
> +; CHECK-NEXT:    ret i1 [[OV1]]
>  ;
>    %s = sub i64 %x, %y
>    store i64 %s, i64* %p
> @@ -190,10 +191,11 @@ define i1 @usubo_ult_i64(i64 %x, i64 %y,
>
>  define i1 @usubo_ugt_i32(i32 %x, i32 %y, i32* %p) {
>  ; CHECK-LABEL: @usubo_ugt_i32(
> -; CHECK-NEXT:    [[OV:%.*]] = icmp ugt i32 [[Y:%.*]], [[X:%.*]]
> -; CHECK-NEXT:    [[S:%.*]] = sub i32 [[X]], [[Y]]
> -; CHECK-NEXT:    store i32 [[S]], i32* [[P:%.*]]
> -; CHECK-NEXT:    ret i1 [[OV]]
> +; CHECK-NEXT:    [[TMP1:%.*]] = call { i32, i1 }
> @llvm.usub.with.overflow.i32(i32 [[X:%.*]], i32 [[Y:%.*]])
> +; CHECK-NEXT:    [[MATH:%.*]] = extractvalue { i32, i1 } [[TMP1]], 0
> +; CHECK-NEXT:    [[OV1:%.*]] = extractvalue { i32, i1 } [[TMP1]], 1
> +; CHECK-NEXT:    store i32 [[MATH]], i32* [[P:%.*]]
> +; CHECK-NEXT:    ret i1 [[OV1]]
>  ;
>    %ov = icmp ugt i32 %y, %x
>    %s = sub i32 %x, %y
> @@ -205,10 +207,11 @@ define i1 @usubo_ugt_i32(i32 %x, i32 %y,
>
>  define i1 @usubo_ugt_constant_op0_i8(i8 %x, i8* %p) {
>  ; CHECK-LABEL: @usubo_ugt_constant_op0_i8(
> -; CHECK-NEXT:    [[S:%.*]] = sub i8 42, [[X:%.*]]
> -; CHECK-NEXT:    [[OV:%.*]] = icmp ugt i8 [[X]], 42
> -; CHECK-NEXT:    store i8 [[S]], i8* [[P:%.*]]
> -; CHECK-NEXT:    ret i1 [[OV]]
> +; CHECK-NEXT:    [[TMP1:%.*]] = call { i8, i1 }
> @llvm.usub.with.overflow.i8(i8 42, i8 [[X:%.*]])
> +; CHECK-NEXT:    [[MATH:%.*]] = extractvalue { i8, i1 } [[TMP1]], 0
> +; CHECK-NEXT:    [[OV1:%.*]] = extractvalue { i8, i1 } [[TMP1]], 1
> +; CHECK-NEXT:    store i8 [[MATH]], i8* [[P:%.*]]
> +; CHECK-NEXT:    ret i1 [[OV1]]
>  ;
>    %s = sub i8 42, %x
>    %ov = icmp ugt i8 %x, 42
> @@ -220,10 +223,11 @@ define i1 @usubo_ugt_constant_op0_i8(i8
>
>  define i1 @usubo_ult_constant_op0_i16(i16 %x, i16* %p) {
>  ; CHECK-LABEL: @usubo_ult_constant_op0_i16(
> -; CHECK-NEXT:    [[S:%.*]] = sub i16 43, [[X:%.*]]
> -; CHECK-NEXT:    [[OV:%.*]] = icmp ult i16 43, [[X]]
> -; CHECK-NEXT:    store i16 [[S]], i16* [[P:%.*]]
> -; CHECK-NEXT:    ret i1 [[OV]]
> +; CHECK-NEXT:    [[TMP1:%.*]] = call { i16, i1 }
> @llvm.usub.with.overflow.i16(i16 43, i16 [[X:%.*]])
> +; CHECK-NEXT:    [[MATH:%.*]] = extractvalue { i16, i1 } [[TMP1]], 0
> +; CHECK-NEXT:    [[OV1:%.*]] = extractvalue { i16, i1 } [[TMP1]], 1
> +; CHECK-NEXT:    store i16 [[MATH]], i16* [[P:%.*]]
> +; CHECK-NEXT:    ret i1 [[OV1]]
>  ;
>    %s = sub i16 43, %x
>    %ov = icmp ult i16 43, %x
> @@ -235,10 +239,11 @@ define i1 @usubo_ult_constant_op0_i16(i1
>
>  define i1 @usubo_ult_constant_op1_i16(i16 %x, i16* %p) {
>  ; CHECK-LABEL: @usubo_ult_constant_op1_i16(
> -; CHECK-NEXT:    [[S:%.*]] = add i16 [[X:%.*]], -44
> -; CHECK-NEXT:    [[OV:%.*]] = icmp ult i16 [[X]], 44
> -; CHECK-NEXT:    store i16 [[S]], i16* [[P:%.*]]
> -; CHECK-NEXT:    ret i1 [[OV]]
> +; CHECK-NEXT:    [[TMP1:%.*]] = call { i16, i1 }
> @llvm.usub.with.overflow.i16(i16 [[X:%.*]], i16 44)
> +; CHECK-NEXT:    [[MATH:%.*]] = extractvalue { i16, i1 } [[TMP1]], 0
> +; CHECK-NEXT:    [[OV1:%.*]] = extractvalue { i16, i1 } [[TMP1]], 1
> +; CHECK-NEXT:    store i16 [[MATH]], i16* [[P:%.*]]
> +; CHECK-NEXT:    ret i1 [[OV1]]
>  ;
>    %s = add i16 %x, -44
>    %ov = icmp ult i16 %x, 44
> @@ -248,10 +253,11 @@ define i1 @usubo_ult_constant_op1_i16(i1
>
>  define i1 @usubo_ugt_constant_op1_i8(i8 %x, i8* %p) {
>  ; CHECK-LABEL: @usubo_ugt_constant_op1_i8(
> -; CHECK-NEXT:    [[OV:%.*]] = icmp ugt i8 45, [[X:%.*]]
> -; CHECK-NEXT:    [[S:%.*]] = add i8 [[X]], -45
> -; CHECK-NEXT:    store i8 [[S]], i8* [[P:%.*]]
> -; CHECK-NEXT:    ret i1 [[OV]]
> +; CHECK-NEXT:    [[TMP1:%.*]] = call { i8, i1 }
> @llvm.usub.with.overflow.i8(i8 [[X:%.*]], i8 45)
> +; CHECK-NEXT:    [[MATH:%.*]] = extractvalue { i8, i1 } [[TMP1]], 0
> +; CHECK-NEXT:    [[OV1:%.*]] = extractvalue { i8, i1 } [[TMP1]], 1
> +; CHECK-NEXT:    store i8 [[MATH]], i8* [[P:%.*]]
> +; CHECK-NEXT:    ret i1 [[OV1]]
>  ;
>    %ov = icmp ugt i8 45, %x
>    %s = add i8 %x, -45
> @@ -263,10 +269,11 @@ define i1 @usubo_ugt_constant_op1_i8(i8
>
>  define i1 @usubo_eq_constant1_op1_i32(i32 %x, i32* %p) {
>  ; CHECK-LABEL: @usubo_eq_constant1_op1_i32(
> -; CHECK-NEXT:    [[S:%.*]] = add i32 [[X:%.*]], -1
> -; CHECK-NEXT:    [[OV:%.*]] = icmp eq i32 [[X]], 0
> -; CHECK-NEXT:    store i32 [[S]], i32* [[P:%.*]]
> -; CHECK-NEXT:    ret i1 [[OV]]
> +; CHECK-NEXT:    [[TMP1:%.*]] = call { i32, i1 }
> @llvm.usub.with.overflow.i32(i32 [[X:%.*]], i32 1)
> +; CHECK-NEXT:    [[MATH:%.*]] = extractvalue { i32, i1 } [[TMP1]], 0
> +; CHECK-NEXT:    [[OV1:%.*]] = extractvalue { i32, i1 } [[TMP1]], 1
> +; CHECK-NEXT:    store i32 [[MATH]], i32* [[P:%.*]]
> +; CHECK-NEXT:    ret i1 [[OV1]]
>  ;
>    %s = add i32 %x, -1
>    %ov = icmp eq i32 %x, 0
> @@ -283,14 +290,15 @@ define i1 @usubo_ult_sub_dominates_i64(i
>  ; CHECK-NEXT:  entry:
>  ; CHECK-NEXT:    br i1 [[COND:%.*]], label [[T:%.*]], label [[F:%.*]]
>  ; CHECK:       t:
> -; CHECK-NEXT:    [[S:%.*]] = sub i64 [[X:%.*]], [[Y:%.*]]
> -; CHECK-NEXT:    store i64 [[S]], i64* [[P:%.*]]
> +; CHECK-NEXT:    [[TMP0:%.*]] = call { i64, i1 }
> @llvm.usub.with.overflow.i64(i64 [[X:%.*]], i64 [[Y:%.*]])
> +; CHECK-NEXT:    [[MATH:%.*]] = extractvalue { i64, i1 } [[TMP0]], 0
> +; CHECK-NEXT:    [[OV1:%.*]] = extractvalue { i64, i1 } [[TMP0]], 1
> +; CHECK-NEXT:    store i64 [[MATH]], i64* [[P:%.*]]
>  ; CHECK-NEXT:    br i1 [[COND]], label [[END:%.*]], label [[F]]
>  ; CHECK:       f:
>  ; CHECK-NEXT:    ret i1 [[COND]]
>  ; CHECK:       end:
> -; CHECK-NEXT:    [[OV:%.*]] = icmp ult i64 [[X]], [[Y]]
> -; CHECK-NEXT:    ret i1 [[OV]]
> +; CHECK-NEXT:    ret i1 [[OV1]]
>  ;
>  entry:
>    br i1 %cond, label %t, label %f
> @@ -319,10 +327,11 @@ define i1 @usubo_ult_cmp_dominates_i64(i
>  ; CHECK:       f:
>  ; CHECK-NEXT:    ret i1 [[COND]]
>  ; CHECK:       end:
> -; CHECK-NEXT:    [[TMP0:%.*]] = icmp ult i64 [[X]], [[Y]]
> -; CHECK-NEXT:    [[S:%.*]] = sub i64 [[X]], [[Y]]
> -; CHECK-NEXT:    store i64 [[S]], i64* [[P:%.*]]
> -; CHECK-NEXT:    ret i1 [[TMP0]]
> +; CHECK-NEXT:    [[TMP0:%.*]] = call { i64, i1 }
> @llvm.usub.with.overflow.i64(i64 [[X]], i64 [[Y]])
> +; CHECK-NEXT:    [[MATH:%.*]] = extractvalue { i64, i1 } [[TMP0]], 0
> +; CHECK-NEXT:    [[OV1:%.*]] = extractvalue { i64, i1 } [[TMP0]], 1
> +; CHECK-NEXT:    store i64 [[MATH]], i64* [[P:%.*]]
> +; CHECK-NEXT:    ret i1 [[OV1]]
>  ;
>  entry:
>    br i1 %cond, label %t, label %f
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>


-- 
Teresa Johnson |  Software Engineer |  tejohnson at google.com |
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