On 5/20/24 5:32 PM, Vineet Gupta wrote:
This is testsuite clean however there's a dwarf quirk which I want to
run by the experts. The test that was tripping CI has following
fragment:
Before patch | After Patch
------------------------------------------------------
li t0,-4096 | addi sp,s0,-2048
addi t0,t0,560 | .cfi_def_cfa 2, 2048 <- #1
add sp,s0,t0 | addi sp,sp,-1488
.cfi_def_cfa 2, 3536 | .cfi_def_cfa_offset 3536 <- #2
addi sp,sp,1504 | addi sp,sp,1504
.cfi_def_cfa_offset 2032 | .cfi_def_cfa_offset 2032 <- #3
The dwarf insn #1 and #3 seem ok, however #2 seems dubious to me.
What about it seems dubious? We need a CFA adjustment on each insn that
modifies the stack pointer so that we can unwind at any arbitrary point.
The first adjustment says the prior frame is at sp + 2048. Then it's at
sp + 3536. Then after the final insn the prior frame is at sp+2032.
Jeff
