forked from OSchip/llvm-project
45 lines
1.5 KiB
LLVM
45 lines
1.5 KiB
LLVM
; RUN: llc -mtriple=x86_64-unknown-linux-gnu -relocation-model=pic < %s | FileCheck %s
|
|
; RUN: llc -mtriple=x86_64-freebsd -relocation-model=pic < %s | FileCheck %s
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;; According to x86-64 psABI, xmm0-xmm7 can be used to pass function parameters.
|
|
;; However regcall calling convention uses also xmm8-xmm15 to pass function
|
|
;; parameters which violates x86-64 psABI.
|
|
;; Detail info about it can be found at:
|
|
;; https://sourceware.org/bugzilla/show_bug.cgi?id=21265
|
|
;;
|
|
;; We encounter the violation symptom when using PIC with lazy binding
|
|
;; optimization.
|
|
;; In that case the PLT mechanism as described in x86_64 psABI will
|
|
;; not preserve xmm8-xmm15 registers and will lead to miscompilation.
|
|
;;
|
|
;; The agreed solution is to disable PLT for regcall calling convention for
|
|
;; SystemV using ELF format.
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
|
|
declare void @lazy()
|
|
declare x86_regcallcc void @regcall_not_lazy()
|
|
|
|
; CHECK-LABEL: foo:
|
|
; CHECK: callq lazy@PLT
|
|
; CHECK: callq *regcall_not_lazy@GOTPCREL(%rip)
|
|
define void @foo() nounwind {
|
|
call void @lazy()
|
|
call void @regcall_not_lazy()
|
|
ret void
|
|
}
|
|
|
|
; CHECK-LABEL: tail_call_regcall:
|
|
; CHECK: jmpq *regcall_not_lazy@GOTPCREL(%rip)
|
|
define void @tail_call_regcall() nounwind {
|
|
tail call void @regcall_not_lazy()
|
|
ret void
|
|
}
|
|
|
|
; CHECK-LABEL: tail_call_regular:
|
|
; CHECK: jmp lazy
|
|
define void @tail_call_regular() nounwind {
|
|
tail call void @lazy()
|
|
ret void
|
|
}
|