8e810dc7d9
When the code is built with -mbackchain, it is possible to retrieve the caller's frame and return addresses. GCC already can do this, add this support to Clang as well. Use RISCVTargetLowering and GCC's s390_return_addr_rtx() as inspiration. Add tests based on what GCC is emitting.
39 lines
968 B
LLVM
39 lines
968 B
LLVM
; Test support for the llvm.returnaddress intrinsic.
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;
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; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
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; The current function's return address is in the link register.
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define ptr @rt0() norecurse nounwind readnone {
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entry:
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; CHECK-LABEL: rt0:
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; CHECK: lgr %r2, %r14
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; CHECK: br %r14
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%0 = tail call ptr @llvm.returnaddress(i32 0)
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ret ptr %0
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}
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; Check the caller's return address.
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define ptr @rtcaller() nounwind "backchain" {
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entry:
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; CHECK-LABEL: rtcaller:
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; CHECK: lg %r1, 0(%r15)
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; CHECK lg %r2, 112(%r1)
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; CHECK: br %r14
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%0 = tail call ptr @llvm.returnaddress(i32 1)
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ret ptr %0
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}
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; Check the caller's caller's return address.
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define ptr @rtcallercaller() nounwind "backchain" {
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entry:
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; CHECK-LABEL: rtcallercaller:
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; CHECK: lg %r1, 0(%r15)
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; CHECK: lg %r1, 0(%r1)
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; CHECK lg %r2, 112(%r1)
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; CHECK: br %r14
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%0 = tail call ptr @llvm.returnaddress(i32 2)
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ret ptr %0
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}
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declare ptr @llvm.returnaddress(i32) nounwind readnone
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