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1; RUN: llc -mtriple=x86_64-unknown-linux-gnu -relocation-model=pic < %s | FileCheck %s2; RUN: llc -mtriple=x86_64-freebsd -relocation-model=pic < %s | FileCheck %s3 4;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;5;; According to x86-64 psABI, xmm0-xmm7 can be used to pass function parameters. 6;; However regcall calling convention uses also xmm8-xmm15 to pass function 7;; parameters which violates x86-64 psABI. 8;; Detail info about it can be found at:9;; https://sourceware.org/bugzilla/show_bug.cgi?id=2126510;;11;; We encounter the violation symptom when using PIC with lazy binding 12;; optimization.13;; In that case the PLT mechanism as described in x86_64 psABI will14;; not preserve xmm8-xmm15 registers and will lead to miscompilation.15;;16;; The agreed solution is to disable PLT for regcall calling convention for 17;; SystemV using ELF format.18;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;19 20declare void @lazy()21declare x86_regcallcc void @regcall_not_lazy()22 23; CHECK-LABEL: foo:24; CHECK: callq lazy@PLT25; CHECK: callq *regcall_not_lazy@GOTPCREL(%rip)26define void @foo() nounwind {27 call void @lazy()28 call void @regcall_not_lazy()29 ret void30}31 32; CHECK-LABEL: tail_call_regcall:33; CHECK: jmpq *regcall_not_lazy@GOTPCREL(%rip)34define void @tail_call_regcall() nounwind {35 tail call void @regcall_not_lazy()36 ret void37}38 39; CHECK-LABEL: tail_call_regular:40; CHECK: jmp lazy41define void @tail_call_regular() nounwind {42 tail call void @lazy()43 ret void44}45