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+; 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
+}