[AArch64] Implement the isZExtFree APIs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205926 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chad Rosier 2014-04-09 20:51:21 +00:00
parent fe5c9cee80
commit c3de5ed072
4 changed files with 55 additions and 1 deletions

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@ -5389,3 +5389,39 @@ bool AArch64TargetLowering::isTruncateFree(EVT VT1, EVT VT2) const {
return false;
return true;
}
// All 32-bit GPR operations implicitly zero the high-half of the corresponding
// 64-bit GPR.
bool AArch64TargetLowering::isZExtFree(Type *Ty1, Type *Ty2) const {
if (!Ty1->isIntegerTy() || !Ty2->isIntegerTy())
return false;
unsigned NumBits1 = Ty1->getPrimitiveSizeInBits();
unsigned NumBits2 = Ty2->getPrimitiveSizeInBits();
if (NumBits1 == 32 && NumBits2 == 64)
return true;
return false;
}
bool AArch64TargetLowering::isZExtFree(EVT VT1, EVT VT2) const {
if (!VT1.isInteger() || !VT2.isInteger())
return false;
unsigned NumBits1 = VT1.getSizeInBits();
unsigned NumBits2 = VT2.getSizeInBits();
if (NumBits1 == 32 && NumBits2 == 64)
return true;
return false;
}
bool AArch64TargetLowering::isZExtFree(SDValue Val, EVT VT2) const {
EVT VT1 = Val.getValueType();
if (isZExtFree(VT1, VT2)) {
return true;
}
if (Val.getOpcode() != ISD::LOAD)
return false;
// 8-, 16-, and 32-bit integer loads all implicitly zero-extend.
return (VT1.isSimple() && VT1.isInteger() && VT2.isSimple() &&
VT2.isInteger() && VT1.getSizeInBits() <= 32);
}

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@ -281,6 +281,10 @@ public:
bool isTruncateFree(Type *Ty1, Type *Ty2) const override;
bool isTruncateFree(EVT VT1, EVT VT2) const override;
bool isZExtFree(Type *Ty1, Type *Ty2) const override;
bool isZExtFree(EVT VT1, EVT VT2) const override;
bool isZExtFree(SDValue Val, EVT VT2) const override;
SDValue getSelectableIntSetCC(SDValue LHS, SDValue RHS, ISD::CondCode CC,
SDValue &A64cc, SelectionDAG &DAG, SDLoc &dl) const;

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@ -0,0 +1,14 @@
; RUN: llc -verify-machineinstrs < %s -mtriple=aarch64-none-linux-gnu | FileCheck %s
define i64 @test_free_zext(i8* %a, i16* %b) {
; CHECK-LABEL: test_free_zext
; CHECK: ldrb w0, [x0]
; CHECK: ldrh w1, [x1]
; CHECK: add x0, x1, x0
%1 = load i8* %a, align 1
%conv = zext i8 %1 to i64
%2 = load i16* %b, align 2
%conv1 = zext i16 %2 to i64
%add = add nsw i64 %conv1, %conv
ret i64 %add
}

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@ -25,7 +25,7 @@ define i64 @test_chains() {
%inc.4 = trunc i64 %inc.3 to i8
store i8 %inc.4, i8* %locvar
; CHECK: ldrb {{w[0-9]+}}, [sp, [[LOCADDR:#[0-9]+]]]
; CHECK: add {{x[0-9]+}}, {{x[0-9]+}}, #1
; CHECK: add {{w[0-9]+}}, {{w[0-9]+}}, #1
; CHECK: strb {{w[0-9]+}}, [sp, [[LOCADDR]]]
; CHECK: ldrb {{w[0-9]+}}, [sp, [[LOCADDR]]]