replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

[WebAssembly] Support combining GEP and FrameIndex offsets in memory operand offset field 

Previously we only supported putting the FI into memory operand offset
fields if there was nothing there already. Now combine them.

Differential Revision: http://reviews.llvm.org/D15941

llvm-svn: 257084
This commit is contained in:
Derek Schuff 2016-01-07 18:55:52 +00:00
parent a4730cf0b4
commit 9bfea27c26
2 changed files with 33 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
llvm/lib/Target/WebAssembly/WebAssemblyRegisterInfo.cpp
View File

@ -61,17 +61,23 @@ void WebAssemblyRegisterInfo::eliminateFrameIndex(
MachineFunction &MF = *MBB.getParent();
int FrameIndex = MI.getOperand(FIOperandNum).getIndex();
const MachineFrameInfo& MFI = *MF.getFrameInfo();
int FrameOffset = MFI.getStackSize() + MFI.getObjectOffset(FrameIndex);
int64_t FrameOffset = MFI.getStackSize() + MFI.getObjectOffset(FrameIndex);
if (MI.mayLoadOrStore()) {
// If this is a load or store, make it relative to SP and fold the frame
// offset directly in
assert(MI.getOperand(1).getImm() == 0 &&
"Can't eliminate FI yet if offset is already set");
MI.getOperand(1).setImm(FrameOffset);
// offset directly in.
assert(FrameOffset >= 0 && MI.getOperand(1).getImm() >= 0);
int64_t Offset = MI.getOperand(1).getImm() + FrameOffset;
if (static_cast<uint64_t>(Offset) > std::numeric_limits<uint32_t>::max()) {
// If this happens the program is invalid, but better to error here than
// generate broken code.
report_fatal_error("Memory offset field overflow");
}
MI.getOperand(1).setImm(Offset);
MI.getOperand(2).ChangeToRegister(WebAssembly::SP32, /*IsDef=*/false);
} else {
// Otherwise create an i32.add SP, offset and make it the operand
// Otherwise create an i32.add SP, offset and make it the operand.
auto &MRI = MF.getRegInfo();
const auto *TII = MF.getSubtarget().getInstrInfo();

21
llvm/test/CodeGen/WebAssembly/userstack.ll
View File

@ -72,6 +72,27 @@ define void @allocarray() {
ret void
}
define void @allocarray_inbounds() {
; CHECK: i32.const [[L1:.+]]=, __stack_pointer
; CHECK-NEXT: i32.load [[L1]]=, 0([[L1]])
; CHECK-NEXT: i32.const [[L2:.+]]=, 32
; CHECK-NEXT: i32.sub [[SP:.+]]=, [[L1]], [[L2]]
%r = alloca [5 x i32]
; CHECK: i32.const $push[[L3:.+]]=, 1
; CHECK: i32.store {{.*}}=, 12([[SP]]), $pop[[L3]]
%p = getelementptr inbounds [5 x i32], [5 x i32]* %r, i32 0, i32 0
store i32 1, i32* %p
; This store should have both the GEP and the FI folded into it.
; CHECK-NEXT: i32.store {{.*}}=, 16([[SP]]), $pop
%p2 = getelementptr inbounds [5 x i32], [5 x i32]* %r, i32 0, i32 1
store i32 1, i32* %p2
; CHECK: i32.const [[L7:.+]]=, 32
; CHECK-NEXT: i32.add [[SP]]=, [[SP]], [[L7]]
; CHECK-NEXT: i32.const [[L8:.+]]=, __stack_pointer
; CHECK-NEXT: i32.store [[SP]]=, 0([[L7]]), [[SP]]
ret void
}
define void @dynamic_alloca(i32 %alloc) {
; TODO: Support frame pointers
;%r = alloca i32, i32 %alloc