forked from OSchip/llvm-project
83cdb654e4
Summary:
When moving add and sub to memory operand instructions,
aarch64-ldst-opt would prematurally pop the stack pointer,
before memory instructions that do access the stack using
indirect loads.
e.g.
```
int foo(int offset){
int local[4] = {0};
return local[offset];
}
```
would generate:
```
sub sp, sp, #16 ; Push the stack
mov x8, sp ; Save stack in register
stp xzr, xzr, [sp], #16 ; Zero initialize stack, and post-increment, making it invalid
------ If an exception goes here, the stack value might be corrupted
ldr w0, [x8, w0, sxtw #2] ; Access correct position, but it is not guarded by SP
```
Reviewers: fhahn, foad, thegameg, eli.friedman, efriedma
Reviewed By: efriedma
Subscribers: efriedma, kristof.beyls, hiraditya, danielkiss, llvm-commits, simon_tatham
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75755
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|---|---|---|
| .. | ||
| AArch64 | ||
| AMDGPU | ||
| ARC | ||
| ARM | ||
| AVR | ||
| BPF | ||
| Generic | ||
| Hexagon | ||
| Inputs | ||
| Lanai | ||
| MIR | ||
| MSP430 | ||
| Mips | ||
| NVPTX | ||
| PowerPC | ||
| RISCV | ||
| SPARC | ||
| SystemZ | ||
| Thumb | ||
| Thumb2 | ||
| VE | ||
| WebAssembly | ||
| WinCFGuard | ||
| WinEH | ||
| X86 | ||
| XCore | ||