[mips] Fix unsigned/signed type error
MipsFastISel uses a a class to represent addresses with a signed member
to represent the offset. MipsFastISel::emitStore, emitLoad and computeAddress
all treated the offset as being positive. In cases where the offset was
actually negative and a frame pointer was used, this would cause the constant
synthesis routine to crash as it would generate an unexpected instruction
sequence when frame indexes are replaced.
Reviewers: vkalintiris
Differential Revision: https://reviews.llvm.org/D26192
llvm-svn: 287099
diff --git a/llvm/lib/Target/Mips/MipsFastISel.cpp b/llvm/lib/Target/Mips/MipsFastISel.cpp
index 895d0f7..cfce60c 100644
--- a/llvm/lib/Target/Mips/MipsFastISel.cpp
+++ b/llvm/lib/Target/Mips/MipsFastISel.cpp
@@ -438,7 +438,7 @@
}
case Instruction::GetElementPtr: {
Address SavedAddr = Addr;
- uint64_t TmpOffset = Addr.getOffset();
+ int64_t TmpOffset = Addr.getOffset();
// Iterate through the GEP folding the constants into offsets where
// we can.
gep_type_iterator GTI = gep_type_begin(U);
@@ -756,7 +756,7 @@
if (Addr.isFIBase()) {
unsigned FI = Addr.getFI();
unsigned Align = 4;
- unsigned Offset = Addr.getOffset();
+ int64_t Offset = Addr.getOffset();
MachineFrameInfo &MFI = MF->getFrameInfo();
MachineMemOperand *MMO = MF->getMachineMemOperand(
MachinePointerInfo::getFixedStack(*MF, FI), MachineMemOperand::MOLoad,
@@ -807,7 +807,7 @@
if (Addr.isFIBase()) {
unsigned FI = Addr.getFI();
unsigned Align = 4;
- unsigned Offset = Addr.getOffset();
+ int64_t Offset = Addr.getOffset();
MachineFrameInfo &MFI = MF->getFrameInfo();
MachineMemOperand *MMO = MF->getMachineMemOperand(
MachinePointerInfo::getFixedStack(*MF, FI), MachineMemOperand::MOStore,
diff --git a/llvm/test/CodeGen/Mips/Fast-ISel/stackloadstore.ll b/llvm/test/CodeGen/Mips/Fast-ISel/stackloadstore.ll
new file mode 100644
index 0000000..421f8ff
--- /dev/null
+++ b/llvm/test/CodeGen/Mips/Fast-ISel/stackloadstore.ll
@@ -0,0 +1,18 @@
+; RUN: llc < %s -march=mipsel -mcpu=mips32 -fast-isel -disable-fp-elim -relocation-model=pic < %s
+
+; Test that negative array access don't crash constant synthesis when fast isel
+; generates negative offsets.
+
+define i16 @test() {
+ %a = alloca [4 x i16], align 4
+ %arrayidx = getelementptr inbounds [4 x i16], [4 x i16]* %a, i32 0, i32 -2
+ %b = load i16, i16* %arrayidx, align 2
+ ret i16 %b
+}
+
+define void @test2() {
+ %a = alloca [4 x i16], align 4
+ %arrayidx = getelementptr inbounds [4 x i16], [4 x i16]* %a, i32 0, i32 -2
+ store i16 2, i16* %arrayidx, align 2
+ ret void
+}