Stream: git-wasmtime

Topic: wasmtime / issue #6301 Use stack args directly from stack...

Wasmtime GitHub notifications bot (Apr 27 2023 at 22:19):

cfallin edited issue #6301:

I would not expect movq 16(%rbp), %rax to be lifted up into block0, as it is only used in block1 and not block2. This results in a load that is not necessary for all possible executions.

test compile precise-output
target x86_64

function %foo(i32, i32, i32, i32, i32, i32, i32) -> i32 {
block0(v0: i32, v1: i32, v2: i32, v3: i32, v4: i32, v5: i32, v6: i32):
    brif v0, block1, block2

block1:
    return v5

block2:
    return v6
}

; VCode:
;   pushq   %rbp
;   movq    %rsp, %rbp
; block0:
;   movq    %r9, %r11
;   movq    16(%rbp), %rax
;   testl   %edi, %edi
;   jnz     label2; j label1
; block1:
;   movq    %rbp, %rsp
;   popq    %rbp
;   ret
; block2:
;   movq    %r11, %rax
;   movq    %rbp, %rsp
;   popq    %rbp
;   ret
;
; Disassembled:
; block0: ; offset 0x0
;   pushq %rbp
;   movq %rsp, %rbp
; block1: ; offset 0x4
;   movq %r9, %r11
;   movq 0x10(%rbp), %rax
;   testl %edi, %edi
;   jne 0x18
; block2: ; offset 0x13
;   movq %rbp, %rsp
;   popq %rbp
;   retq
; block3: ; offset 0x18
;   movq %r11, %rax
;   movq %rbp, %rsp
;   popq %rbp
;   retq

Last updated: Dec 23 2024 at 12:05 UTC