50a97aacac
Re-commit of 32e8b550e5439c7e4aafa73894faffd5f25d0d05 This patch rearranges emission of CFI instructions, so the resulting DWARF and `.eh_frame` information is precise at every instruction. The current state is that the unwind info is emitted only after the function prologue. This is fine for synchronous (e.g. C++) exceptions, but the information is generally incorrect when the program counter is at an instruction in the prologue or the epilogue, for example: ``` stp x29, x30, [sp, #-16]! // 16-byte Folded Spill mov x29, sp .cfi_def_cfa w29, 16 ... ``` after the `stp` is executed the (initial) rule for the CFA still says the CFA is in the `sp`, even though it's already offset by 16 bytes A correct unwind info could look like: ``` stp x29, x30, [sp, #-16]! // 16-byte Folded Spill .cfi_def_cfa_offset 16 mov x29, sp .cfi_def_cfa w29, 16 ... ``` Having this information precise up to an instruction is useful for sampling profilers that would like to get a stack backtrace. The end goal (towards this patch is just a step) is to have fully working `-fasynchronous-unwind-tables`. Reviewed By: danielkiss, MaskRay Differential Revision: https://reviews.llvm.org/D111411
104 lines
3.6 KiB
LLVM
104 lines
3.6 KiB
LLVM
; RUN: llc -verify-machineinstrs -enable-machine-outliner -mtriple=aarch64-arm-none-eabi -frame-pointer=non-leaf < %s | FileCheck %s --check-prefix=NOOMIT
|
|
; RUN: llc -verify-machineinstrs -enable-machine-outliner -mtriple=aarch64-arm-none-eabi -frame-pointer=none < %s | FileCheck %s --check-prefix=OMITFP
|
|
|
|
define void @_Z1giii(i32 %x, i32 %y, i32 %z) minsize {
|
|
; NOOMIT-LABEL: _Z1giii:
|
|
; NOOMIT: // %bb.0: // %entry
|
|
; NOOMIT-NEXT: b _Z1hiii
|
|
;
|
|
; OMITFP-LABEL: _Z1giii:
|
|
; OMITFP: // %bb.0: // %entry
|
|
; OMITFP-NEXT: b _Z1hiii
|
|
entry:
|
|
tail call void @_Z1hiii(i32 %x, i32 %y, i32 %z)
|
|
ret void
|
|
}
|
|
|
|
declare void @_Z1hiii(i32, i32, i32) minsize
|
|
|
|
define void @_Z2f1v() minsize {
|
|
; NOOMIT-LABEL: _Z2f1v:
|
|
; NOOMIT: // %bb.0: // %entry
|
|
; NOOMIT-NEXT: stp x29, x30, [sp, #-16]! // 16-byte Folded Spill
|
|
; NOOMIT-NEXT: .cfi_def_cfa_offset 16
|
|
; NOOMIT-NEXT: mov x29, sp
|
|
; NOOMIT-NEXT: .cfi_def_cfa w29, 16
|
|
; NOOMIT-NEXT: .cfi_offset w30, -8
|
|
; NOOMIT-NEXT: .cfi_offset w29, -16
|
|
; NOOMIT-NEXT: bl OUTLINED_FUNCTION_0
|
|
; NOOMIT-NEXT: ldp x29, x30, [sp], #16 // 16-byte Folded Reload
|
|
; NOOMIT-NEXT: b _Z1giii
|
|
;
|
|
; OMITFP-LABEL: _Z2f1v:
|
|
; OMITFP: // %bb.0: // %entry
|
|
; OMITFP-NEXT: str x30, [sp, #-16]! // 8-byte Folded Spill
|
|
; OMITFP-NEXT: .cfi_def_cfa_offset 16
|
|
; OMITFP-NEXT: .cfi_offset w30, -16
|
|
; OMITFP-NEXT: bl OUTLINED_FUNCTION_0
|
|
; OMITFP-NEXT: ldr x30, [sp], #16 // 8-byte Folded Reload
|
|
; OMITFP-NEXT: b _Z1giii
|
|
entry:
|
|
tail call void @_Z1giii(i32 1, i32 2, i32 3)
|
|
tail call void @_Z1giii(i32 1, i32 2, i32 3)
|
|
ret void
|
|
}
|
|
|
|
define void @_Z2f2v() minsize {
|
|
; NOOMIT-LABEL: _Z2f2v:
|
|
; NOOMIT: // %bb.0: // %entry
|
|
; NOOMIT-NEXT: stp x29, x30, [sp, #-16]! // 16-byte Folded Spill
|
|
; NOOMIT-NEXT: .cfi_def_cfa_offset 16
|
|
; NOOMIT-NEXT: mov x29, sp
|
|
; NOOMIT-NEXT: .cfi_def_cfa w29, 16
|
|
; NOOMIT-NEXT: .cfi_offset w30, -8
|
|
; NOOMIT-NEXT: .cfi_offset w29, -16
|
|
; NOOMIT-NEXT: bl OUTLINED_FUNCTION_0
|
|
; NOOMIT-NEXT: ldp x29, x30, [sp], #16 // 16-byte Folded Reload
|
|
; NOOMIT-NEXT: b _Z1giii
|
|
;
|
|
; OMITFP-LABEL: _Z2f2v:
|
|
; OMITFP: // %bb.0: // %entry
|
|
; OMITFP-NEXT: str x30, [sp, #-16]! // 8-byte Folded Spill
|
|
; OMITFP-NEXT: .cfi_def_cfa_offset 16
|
|
; OMITFP-NEXT: .cfi_offset w30, -16
|
|
; OMITFP-NEXT: bl OUTLINED_FUNCTION_0
|
|
; OMITFP-NEXT: ldr x30, [sp], #16 // 8-byte Folded Reload
|
|
; OMITFP-NEXT: b _Z1giii
|
|
entry:
|
|
tail call void @_Z1giii(i32 1, i32 2, i32 3)
|
|
tail call void @_Z1giii(i32 1, i32 2, i32 3)
|
|
ret void
|
|
}
|
|
|
|
; OMITFP-LABEL: OUTLINED_FUNCTION_0:
|
|
; OMITFP: .cfi_startproc
|
|
; OMITFP-NEXT: // %bb.0:
|
|
; OMITFP-NEXT: .cfi_def_cfa_offset 16
|
|
; OMITFP-NEXT: .cfi_offset w30, -16
|
|
; OMITFP-NEXT: str x30, [sp, #-16]!
|
|
; OMITFP-NEXT: mov w0, #1
|
|
; OMITFP-NEXT: mov w1, #2
|
|
; OMITFP-NEXT: mov w2, #3
|
|
; OMITFP-NEXT: bl _Z1giii
|
|
; OMITFP-NEXT: mov w0, #1
|
|
; OMITFP-NEXT: mov w1, #2
|
|
; OMITFP-NEXT: mov w2, #3
|
|
; OMITFP-NEXT: ldr x30, [sp], #16
|
|
; OMITFP-NEXT: ret
|
|
|
|
; NOOMIT-LABEL: OUTLINED_FUNCTION_0:
|
|
; NOOMIT: .cfi_startproc
|
|
; NOOMIT-NEXT: // %bb.0:
|
|
; NOOMIT-NEXT: .cfi_def_cfa_offset 16
|
|
; NOOMIT-NEXT: .cfi_offset w30, -16
|
|
; NOOMIT-NEXT: str x30, [sp, #-16]!
|
|
; NOOMIT-NEXT: mov w0, #1
|
|
; NOOMIT-NEXT: mov w1, #2
|
|
; NOOMIT-NEXT: mov w2, #3
|
|
; NOOMIT-NEXT: bl _Z1giii
|
|
; NOOMIT-NEXT: mov w0, #1
|
|
; NOOMIT-NEXT: mov w1, #2
|
|
; NOOMIT-NEXT: mov w2, #3
|
|
; NOOMIT-NEXT: ldr x30, [sp], #16
|
|
; NOOMIT-NEXT: ret
|