Fix a crash on invalid code due to memcpy lowering.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44378 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2007-11-27 22:14:42 +00:00
parent a8d700138a
commit 789db09cde
3 changed files with 70 additions and 26 deletions

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@ -779,35 +779,40 @@ void PPCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
// to Offset to get the correct offset.
Offset += MFI->getStackSize();
if (isInt16(Offset)) {
if (isIXAddr) {
assert((Offset & 3) == 0 && "Invalid frame offset!");
// If we can, encode the offset directly into the instruction. If this is a
// normal PPC "ri" instruction, any 16-bit value can be safely encoded. If
// this is a PPC64 "ix" instruction, only a 16-bit value with the low two bits
// clear can be encoded. This is extremely uncommon, because normally you
// only "std" to a stack slot that is at least 4-byte aligned, but it can
// happen in invalid code.
if (isInt16(Offset) && (!isIXAddr || (isIXAddr & 3) == 0)) {
if (isIXAddr)
Offset >>= 2; // The actual encoded value has the low two bits zero.
}
MI.getOperand(OffsetOperandNo).ChangeToImmediate(Offset);
} else {
// Insert a set of r0 with the full offset value before the ld, st, or add
BuildMI(MBB, II, TII.get(PPC::LIS), PPC::R0).addImm(Offset >> 16);
BuildMI(MBB, II, TII.get(PPC::ORI), PPC::R0).addReg(PPC::R0).addImm(Offset);
// Convert into indexed form of the instruction
// sth 0:rA, 1:imm 2:(rB) ==> sthx 0:rA, 2:rB, 1:r0
// addi 0:rA 1:rB, 2, imm ==> add 0:rA, 1:rB, 2:r0
unsigned OperandBase;
if (OpC != TargetInstrInfo::INLINEASM) {
assert(ImmToIdxMap.count(OpC) &&
"No indexed form of load or store available!");
unsigned NewOpcode = ImmToIdxMap.find(OpC)->second;
MI.setInstrDescriptor(TII.get(NewOpcode));
OperandBase = 1;
} else {
OperandBase = OffsetOperandNo;
}
unsigned StackReg = MI.getOperand(FIOperandNo).getReg();
MI.getOperand(OperandBase).ChangeToRegister(StackReg, false);
MI.getOperand(OperandBase+1).ChangeToRegister(PPC::R0, false);
return;
}
// Insert a set of r0 with the full offset value before the ld, st, or add
BuildMI(MBB, II, TII.get(PPC::LIS), PPC::R0).addImm(Offset >> 16);
BuildMI(MBB, II, TII.get(PPC::ORI), PPC::R0).addReg(PPC::R0).addImm(Offset);
// Convert into indexed form of the instruction
// sth 0:rA, 1:imm 2:(rB) ==> sthx 0:rA, 2:rB, 1:r0
// addi 0:rA 1:rB, 2, imm ==> add 0:rA, 1:rB, 2:r0
unsigned OperandBase;
if (OpC != TargetInstrInfo::INLINEASM) {
assert(ImmToIdxMap.count(OpC) &&
"No indexed form of load or store available!");
unsigned NewOpcode = ImmToIdxMap.find(OpC)->second;
MI.setInstrDescriptor(TII.get(NewOpcode));
OperandBase = 1;
} else {
OperandBase = OffsetOperandNo;
}
unsigned StackReg = MI.getOperand(FIOperandNo).getReg();
MI.getOperand(OperandBase).ChangeToRegister(StackReg, false);
MI.getOperand(OperandBase+1).ChangeToRegister(PPC::R0, false);
}
/// VRRegNo - Map from a numbered VR register to its enum value.

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@ -0,0 +1,19 @@
; RUN: llvm-as < %s | llc
; This testcase is invalid (the alignment specified for memcpy is
; greater than the alignment guaranteed for Qux or C.0.1173), but it
; should compile, not crash the code generator.
@C.0.1173 = external constant [33 x i8] ; <[33 x i8]*> [#uses=1]
define void @Bork() {
entry:
%Qux = alloca [33 x i8] ; <[33 x i8]*> [#uses=1]
%Qux1 = bitcast [33 x i8]* %Qux to i8* ; <i8*> [#uses=1]
call void @llvm.memcpy.i64( i8* %Qux1, i8* getelementptr ([33 x i8]* @C.0.1173, i32 0, i32 0), i64 33, i32 8 )
ret void
}
declare void @llvm.memcpy.i64(i8*, i8*, i64, i32)

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@ -0,0 +1,20 @@
; RUN: llvm-as < %s | llc -march=ppc32
; RUN: llvm-as < %s | llc -march=ppc64
; This testcase is invalid (the alignment specified for memcpy is
; greater than the alignment guaranteed for Qux or C.0.1173, but it
; should compile, not crash the code generator.
@C.0.1173 = external constant [33 x i8] ; <[33 x i8]*> [#uses=1]
define void @Bork() {
entry:
%Qux = alloca [33 x i8] ; <[33 x i8]*> [#uses=1]
%Qux1 = bitcast [33 x i8]* %Qux to i8* ; <i8*> [#uses=1]
call void @llvm.memcpy.i64( i8* %Qux1, i8* getelementptr ([33 x i8]* @C.0.1173, i32 0, i32 0), i64 33, i32 8 )
ret void
}
declare void @llvm.memcpy.i64(i8*, i8*, i64, i32)