1 ; RUN: llc -mtriple=x86_64-apple-macosx -mattr=+cx16 -x86-use-base-pointer=true -stackrealign -stack-alignment=32 %s -o - | FileCheck --check-prefix=CHECK --check-prefix=USE_BASE --check-prefix=USE_BASE_64 %s 2 ; RUN: llc -mtriple=x86_64-apple-macosx -mattr=+cx16 -x86-use-base-pointer=false -stackrealign -stack-alignment=32 %s -o - | FileCheck --check-prefix=CHECK --check-prefix=DONT_USE_BASE %s 3 ; RUN: llc -mtriple=x86_64-linux-gnux32 -mattr=+cx16 -x86-use-base-pointer=true -stackrealign -stack-alignment=32 %s -o - | FileCheck --check-prefix=CHECK --check-prefix=USE_BASE --check-prefix=USE_BASE_32 %s 4 ; RUN: llc -mtriple=x86_64-linux-gnux32 -mattr=+cx16 -x86-use-base-pointer=false -stackrealign -stack-alignment=32 %s -o - | FileCheck --check-prefix=CHECK --check-prefix=DONT_USE_BASE %s 5 6 ; This function uses dynamic allocated stack to force the use 7 ; of a frame pointer. 8 ; The inline asm clobbers a bunch of registers to make sure 9 ; the frame pointer will need to be used (for spilling in that case). 10 ; 11 ; Then, we check that when we use rbx as the base pointer, 12 ; we do not use cmpxchg, since using that instruction requires 13 ; to clobbers rbx to set the arguments of the instruction and when 14 ; rbx is used as the base pointer, RA cannot fix the code for us. 15 ; 16 ; CHECK-LABEL: cmp_and_swap16: 17 ; Check that we actually use rbx. 18 ; gnux32 use the 32bit variant of the registers. 19 ; USE_BASE_64: movq %rsp, %rbx 20 ; USE_BASE_32: movl %esp, %ebx 21 ; 22 ; Make sure the base pointer is saved before the RBX argument for 23 ; cmpxchg16b is set. 24 ; 25 ; Because of how the test is written, we spill SAVE_RBX. 26 ; However, it would have been perfectly fine to just keep it in register. 27 ; USE_BASE: movq %rbx, [[SAVE_RBX_SLOT:[0-9]*\(%[er]bx\)]] 28 ; 29 ; SAVE_RBX must be in register before we clobber rbx. 30 ; It is fine to use any register but rbx and the ones defined and use 31 ; by cmpxchg. Since such regex would be complicated to write, just stick 32 ; to the numbered registers. The bottom line is: if this test case fails 33 ; because of that regex, this is likely just the regex being too conservative. 34 ; USE_BASE: movq [[SAVE_RBX_SLOT]], [[SAVE_RBX:%r[0-9]+]] 35 ; 36 ; USE_BASE: movq {{[^ ]+}}, %rbx 37 ; USE_BASE-NEXT: cmpxchg16b 38 ; USE_BASE-NEXT: movq [[SAVE_RBX]], %rbx 39 ; 40 ; DONT_USE_BASE-NOT: movq %rsp, %rbx 41 ; DONT_USE_BASE-NOT: movl %esp, %ebx 42 ; DONT_USE_BASE: cmpxchg 43 define i1 @cmp_and_swap16(i128 %a, i128 %b, i128* %addr, i32 %n) { 44 %dummy = alloca i32, i32 %n 45 tail call void asm sideeffect "nop", "~{rax},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15}"() 46 %cmp = cmpxchg i128* %addr, i128 %a, i128 %b seq_cst seq_cst 47 %res = extractvalue { i128, i1 } %cmp, 1 48 %idx = getelementptr i32, i32* %dummy, i32 5 49 store i32 %n, i32* %idx 50 ret i1 %res 51 } 52
