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llvm-project/llvm/test/CodeGen/AArch64/taildup-cfi.ll

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[DWARF] Allow duplication of tails with CFI instructions This commit came as a result for revert of patch r317579 (originally committed as r317100). The patch made CFI instructions duplicable, because their existence in the epilogue block was affecting the Tail duplication pass. However, duplicating blocks with CFI instructions was an issue for compact unwind info on Darwin, which is why the patch was reverted. This patch allows duplicating tails with CFI instructions, though they are not duplicable, by copying them 'manually'. Patch by Djordje Kovacevic. Differential Revision: https://reviews.llvm.org/D40979 llvm-svn: 323883
2018-01-31 23:57:57 +08:00
; REQUIRES: asserts
; RUN: llc -mtriple=arm64-unknown-linux-gnu -debug-only=tailduplication %s -o /dev/null 2>&1 | FileCheck %s --check-prefix=LINUX
; RUN: llc -mtriple=arm64-apple-darwin -debug-only=tailduplication %s -o /dev/null 2>&1 | FileCheck %s --check-prefix=DARWIN
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
@g = common local_unnamed_addr global i32 0, align 4
@f = common local_unnamed_addr global i32 0, align 4
@a = common local_unnamed_addr global i32 0, align 4
@m = common local_unnamed_addr global i32 0, align 4
@l = common local_unnamed_addr global i32 0, align 4
@j = common local_unnamed_addr global i32 0, align 4
@k = common local_unnamed_addr global i32 0, align 4
@i = common local_unnamed_addr global i32 0, align 4
@d = common local_unnamed_addr global i32 0, align 4
@c = common local_unnamed_addr global i32 0, align 4
@e = common local_unnamed_addr global i32 0, align 4
@h = common local_unnamed_addr global i32 0, align 4
; Function Attrs: norecurse nounwind uwtable
define void @n(i32 %o, i32* nocapture readonly %b) local_unnamed_addr #0 {
entry:
%0 = load i32, i32* @g, align 4, !tbaa !2
%tobool = icmp eq i32 %0, 0
br i1 %tobool, label %entry.if.end_crit_edge, label %if.then
entry.if.end_crit_edge: ; preds = %entry
%.pre = load i32, i32* @f, align 4, !tbaa !2
br label %if.end
if.then: ; preds = %entry
store i32 0, i32* @f, align 4, !tbaa !2
br label %if.end
[FIX] Forces shrink wrapping to consider any memory access as aliasing with the stack Summary: Relate bug: https://bugs.llvm.org/show_bug.cgi?id=37472 The shrink wrapping pass prematurally restores the stack, at a point where the stack might still be accessed. Taking an exception can cause the stack to be corrupted. As a first approach, this patch is overly conservative, assuming that any instruction that may load or store could access the stack. Reviewers: dmgreen, qcolombet Reviewed By: qcolombet Subscribers: simpal01, efriedma, eli.friedman, javed.absar, llvm-commits, eugenis, chill, carwil, thegameg Tags: #llvm Differential Revision: https://reviews.llvm.org/D63152 llvm-svn: 363265
2019-06-13 21:56:19 +08:00
; DARWIN: Merging into block
[DWARF] Allow duplication of tails with CFI instructions This commit came as a result for revert of patch r317579 (originally committed as r317100). The patch made CFI instructions duplicable, because their existence in the epilogue block was affecting the Tail duplication pass. However, duplicating blocks with CFI instructions was an issue for compact unwind info on Darwin, which is why the patch was reverted. This patch allows duplicating tails with CFI instructions, though they are not duplicable, by copying them 'manually'. Patch by Djordje Kovacevic. Differential Revision: https://reviews.llvm.org/D40979 llvm-svn: 323883
2018-01-31 23:57:57 +08:00
; LINUX: Merging into block
if.end: ; preds = %entry.if.end_crit_edge, %if.then
%1 = phi i32 [ %.pre, %entry.if.end_crit_edge ], [ 0, %if.then ]
%cmp6 = icmp slt i32 %1, %o
br i1 %cmp6, label %for.body.lr.ph, label %for.end
for.body.lr.ph: ; preds = %if.end
%.pre7 = load i32, i32* @a, align 4, !tbaa !2
%.pre8 = load i32, i32* @l, align 4, !tbaa !2
%.pre9 = load i32, i32* @j, align 4, !tbaa !2
%.pre10 = load i32, i32* @k, align 4, !tbaa !2
%.pre11 = load i32, i32* @i, align 4, !tbaa !2
br label %for.body
for.body: ; preds = %if.end5, %for.body.lr.ph
%2 = phi i32 [ %.pre11, %for.body.lr.ph ], [ %7, %if.end5 ]
%3 = phi i32 [ %.pre10, %for.body.lr.ph ], [ %8, %if.end5 ]
%4 = phi i32 [ %.pre9, %for.body.lr.ph ], [ %9, %if.end5 ]
%5 = phi i32 [ %1, %for.body.lr.ph ], [ %inc, %if.end5 ]
store i32 %.pre7, i32* @m, align 4, !tbaa !2
%mul = mul nsw i32 %3, %4
%cmp1 = icmp sgt i32 %.pre8, %mul
%conv = zext i1 %cmp1 to i32
%cmp2 = icmp slt i32 %2, %conv
br i1 %cmp2, label %if.then4, label %if.end5
if.then4: ; preds = %for.body
%6 = load i32, i32* @d, align 4, !tbaa !2
store i32 %6, i32* @k, align 4, !tbaa !2
store i32 %6, i32* @i, align 4, !tbaa !2
store i32 %6, i32* @j, align 4, !tbaa !2
br label %if.end5
if.end5: ; preds = %if.then4, %for.body
%7 = phi i32 [ %6, %if.then4 ], [ %2, %for.body ]
%8 = phi i32 [ %6, %if.then4 ], [ %3, %for.body ]
%9 = phi i32 [ %6, %if.then4 ], [ %4, %for.body ]
%10 = load i32, i32* @c, align 4, !tbaa !2
%idxprom = sext i32 %10 to i64
%arrayidx = getelementptr inbounds i32, i32* %b, i64 %idxprom
%11 = load i32, i32* %arrayidx, align 4, !tbaa !2
%12 = load i32, i32* @e, align 4, !tbaa !2
%sub = sub nsw i32 %11, %12
store i32 %sub, i32* @h, align 4, !tbaa !2
%inc = add nsw i32 %5, 1
store i32 %inc, i32* @f, align 4, !tbaa !2
%exitcond = icmp eq i32 %inc, %o
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %if.end5, %if.end
ret void
}
attributes #0 = { norecurse nounwind uwtable }
!2 = !{!3, !3, i64 0}
!3 = !{!"int", !4, i64 0}
!4 = !{}