Fix integer undefined behavior due to signed left shift overflow in LLVM.
Reviewed offline by chandlerc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162623 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index c18ba69..8807824 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -811,14 +811,13 @@
}
// Properly sign extend the value.
- int ShAmt = (4-ByteSize)*8;
- int MaskVal = ((int)Value << ShAmt) >> ShAmt;
+ int MaskVal = SignExtend32(Value, ByteSize * 8);
// If this is zero, don't match, zero matches ISD::isBuildVectorAllZeros.
if (MaskVal == 0) return SDValue();
// Finally, if this value fits in a 5 bit sext field, return it
- if (((MaskVal << (32-5)) >> (32-5)) == MaskVal)
+ if (SignExtend32<5>(MaskVal) == MaskVal)
return DAG.getTargetConstant(MaskVal, MVT::i32);
return SDValue();
}
@@ -2424,7 +2423,7 @@
int Addr = C->getZExtValue();
if ((Addr & 3) != 0 || // Low 2 bits are implicitly zero.
- (Addr << 6 >> 6) != Addr)
+ SignExtend32<26>(Addr) != Addr)
return 0; // Top 6 bits have to be sext of immediate.
return DAG.getConstant((int)C->getZExtValue() >> 2,
@@ -4142,7 +4141,7 @@
unsigned TypeShiftAmt = i & (SplatBitSize-1);
// vsplti + shl self.
- if (SextVal == (i << (int)TypeShiftAmt)) {
+ if (SextVal == (int)((unsigned)i << TypeShiftAmt)) {
SDValue Res = BuildSplatI(i, SplatSize, MVT::Other, DAG, dl);
static const unsigned IIDs[] = { // Intrinsic to use for each size.
Intrinsic::ppc_altivec_vslb, Intrinsic::ppc_altivec_vslh, 0,
@@ -4187,17 +4186,17 @@
}
// t = vsplti c, result = vsldoi t, t, 1
- if (SextVal == ((i << 8) | (i < 0 ? 0xFF : 0))) {
+ if (SextVal == (int)(((unsigned)i << 8) | (i < 0 ? 0xFF : 0))) {
SDValue T = BuildSplatI(i, SplatSize, MVT::v16i8, DAG, dl);
return BuildVSLDOI(T, T, 1, Op.getValueType(), DAG, dl);
}
// t = vsplti c, result = vsldoi t, t, 2
- if (SextVal == ((i << 16) | (i < 0 ? 0xFFFF : 0))) {
+ if (SextVal == (int)(((unsigned)i << 16) | (i < 0 ? 0xFFFF : 0))) {
SDValue T = BuildSplatI(i, SplatSize, MVT::v16i8, DAG, dl);
return BuildVSLDOI(T, T, 2, Op.getValueType(), DAG, dl);
}
// t = vsplti c, result = vsldoi t, t, 3
- if (SextVal == ((i << 24) | (i < 0 ? 0xFFFFFF : 0))) {
+ if (SextVal == (int)(((unsigned)i << 24) | (i < 0 ? 0xFFFFFF : 0))) {
SDValue T = BuildSplatI(i, SplatSize, MVT::v16i8, DAG, dl);
return BuildVSLDOI(T, T, 3, Op.getValueType(), DAG, dl);
}