[X86ISelLowering] Fix TLSADDR lowering when shrink-wrapping is enabled.
TLSADDR nodes are lowered into actuall calls inside MC. In order to prevent
shrink-wrapping from pushing prologue/epilogue past them (which result
in TLS variables being accessed before the stack frame is set up), we
put markers, so that the stack gets adjusted properly.
Thanks to Quentin Colombet for guidance/help on how to fix this problem!
llvm-svn: 261387
diff --git a/llvm/test/CodeGen/X86/tls-shrink-wrapping.ll b/llvm/test/CodeGen/X86/tls-shrink-wrapping.ll
new file mode 100644
index 0000000..37c1754
--- /dev/null
+++ b/llvm/test/CodeGen/X86/tls-shrink-wrapping.ll
@@ -0,0 +1,60 @@
+; Testcase generated from the following code:
+; extern __thread int i;
+; void f();
+; int g(void) {
+; if (i) {
+; i = 0;
+; f();
+; }
+; return i;
+; }
+; We want to make sure that TLS variables are not accessed before
+; the stack frame is set up.
+
+; RUN: llc < %s -relocation-model=pic | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-freebsd11.0"
+
+@i = external thread_local global i32, align 4
+
+define i32 @g() #0 {
+entry:
+ %tmp = load i32, i32* @i, align 4
+ %tobool = icmp eq i32 %tmp, 0
+ br i1 %tobool, label %if.end, label %if.then
+
+if.then: ; preds = %entry
+ store i32 0, i32* @i, align 4
+ tail call void (...) @f() #2
+ %.pre = load i32, i32* @i, align 4
+ br label %if.end
+
+if.end: ; preds = %if.then, %entry
+ %tmp1 = phi i32 [ 0, %entry ], [ %.pre, %if.then ]
+ ret i32 %tmp1
+}
+
+; CHECK: g: # @g
+; CHECK-NEXT: .cfi_startproc
+; CHECK-NEXT: # BB#0: # %entry
+; CHECK-NEXT: pushq %rbp
+; CHECK-NEXT: .Ltmp0:
+; CHECK-NEXT: .cfi_def_cfa_offset 16
+; CHECK-NEXT: .Ltmp1:
+; CHECK-NEXT: .cfi_offset %rbp, -16
+; CHECK-NEXT: movq %rsp, %rbp
+; CHECK-NEXT: .Ltmp2:
+; CHECK-NEXT: .cfi_def_cfa_register %rbp
+; CHECK-NEXT: pushq %rbx
+; CHECK-NEXT: pushq %rax
+; CHECK-NEXT: .Ltmp3:
+; CHECK-NEXT: .cfi_offset %rbx, -24
+; CHECK-NEXT: data16
+; CHECK-NEXT: leaq i@TLSGD(%rip), %rdi
+
+declare void @f(...) #1
+
+attributes #0 = { nounwind uwtable "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #2 = { nounwind }