Fix for PR 26356

Using the load immediate only when the immediate (whether signed or unsigned)
can fit in a 16-bit signed field. Namely, from -32768 to 32767 for signed and
0 to 65535 for unsigned. This patch also ensures that we sign-extend under the
right conditions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259840 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nemanja Ivanovic 2016-02-04 23:14:42 +00:00
parent cb8e306b6b
commit e0a5f73cd5
2 changed files with 140 additions and 5 deletions

View File

@ -1615,7 +1615,7 @@ bool PPCFastISel::SelectRet(const Instruction *I) {
// extension rather than sign extension. Make sure we pass the return
// value extension property to integer materialization.
unsigned SrcReg =
PPCMaterializeInt(CI, MVT::i64, VA.getLocInfo() == CCValAssign::SExt);
PPCMaterializeInt(CI, MVT::i64, VA.getLocInfo() != CCValAssign::ZExt);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), RetReg).addReg(SrcReg);
@ -2090,22 +2090,21 @@ unsigned PPCFastISel::PPCMaterializeInt(const ConstantInt *CI, MVT VT,
const TargetRegisterClass *RC =
((VT == MVT::i64) ? &PPC::G8RCRegClass : &PPC::GPRCRegClass);
int64_t Imm = UseSExt ? CI->getSExtValue() : CI->getZExtValue();
// If the constant is in range, use a load-immediate.
// Since LI will sign extend the constant we need to make sure that for
// our zeroext constants that the sign extended constant fits into 16-bits -
// a range of 0..0x7fff.
if ((UseSExt && isInt<16>(CI->getSExtValue())) ||
(!UseSExt && isUInt<16>(CI->getSExtValue()))) {
if (isInt<16>(Imm)) {
unsigned Opc = (VT == MVT::i64) ? PPC::LI8 : PPC::LI;
unsigned ImmReg = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ImmReg)
.addImm(CI->getSExtValue());
.addImm(Imm);
return ImmReg;
}
// Construct the constant piecewise.
int64_t Imm = UseSExt ? CI->getSExtValue() : CI->getZExtValue();
if (VT == MVT::i64)
return PPCMaterialize64BitInt(Imm, RC);
else if (VT == MVT::i32)

View File

@ -0,0 +1,136 @@
; RUN: llc -O0 -mcpu=pwr7 -mtriple=powerpc64le-unknown-unknown < %s | FileCheck %s
define zeroext i32 @f1() {
entry:
ret i32 65535
}
; CHECK-LABEL: @f1
; CHECK: lis 3, 0
; CHECK: ori 3, 3, 65535
define zeroext i32 @f2() {
entry:
ret i32 32768
}
; CHECK-LABEL: @f2
; CHECK: lis 3, 0
; CHECK: ori 3, 3, 32768
define zeroext i32 @f3() {
entry:
ret i32 32767
}
; CHECK-LABEL: @f3
; CHECK: li 3, 32767
define zeroext i16 @f4() {
entry:
ret i16 65535
}
; CHECK-LABEL: @f4
; CHECK: lis 3, 0
; CHECK: ori 3, 3, 65535
define zeroext i16 @f5() {
entry:
ret i16 32768
}
; CHECK-LABEL: @f5
; CHECK: lis 3, 0
; CHECK: ori 3, 3, 32768
define zeroext i16 @f6() {
entry:
ret i16 32767
}
; CHECK-LABEL: @f6
; CHECK: li 3, 32767
define zeroext i16 @f7() {
entry:
ret i16 -1
}
; CHECK-LABEL: @f7
; CHECK: lis 3, 0
; CHECK: ori 3, 3, 65535
define zeroext i16 @f8() {
entry:
ret i16 -32768
}
; CHECK-LABEL: @f8
; CHECK: lis 3, 0
; CHECK: ori 3, 3, 32768
define signext i32 @f1s() {
entry:
ret i32 65535
}
; CHECK-LABEL: @f1s
; CHECK: lis 3, 0
; CHECK: ori 3, 3, 65535
define signext i32 @f2s() {
entry:
ret i32 32768
}
; CHECK-LABEL: @f2s
; CHECK: lis 3, 0
; CHECK: ori 3, 3, 32768
define signext i32 @f3s() {
entry:
ret i32 32767
}
; CHECK-LABEL: @f3s
; CHECK: li 3, 32767
define signext i16 @f4s() {
entry:
ret i16 32767
}
; CHECK-LABEL: @f4s
; CHECK: li 3, 32767
define signext i32 @f1sn() {
entry:
ret i32 -65535
}
; CHECK-LABEL: @f1sn
; CHECK: lis 3, -1
; CHECK: ori 3, 3, 1
define signext i32 @f2sn() {
entry:
ret i32 -32768
}
; CHECK-LABEL: @f2sn
; CHECK: li 3, -32768
define signext i32 @f3sn() {
entry:
ret i32 -32767
}
; CHECK-LABEL: @f3sn
; CHECK: li 3, -32767
define signext i32 @f4sn() {
entry:
ret i32 -65536
}
; CHECK-LABEL: @f4sn
; CHECK: lis 3, -1
define signext i16 @f5sn() {
entry:
ret i16 -32767
}
; CHECK-LABEL: @f5sn
; CHECK: li 3, -32767
define signext i16 @f6sn() {
entry:
ret i16 -32768
}
; CHECK-LABEL: @f6sn
; CHECK: li 3, -32768