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llvm-project/llvm/test/CodeGen/Thumb2/2010-11-22-EpilogueBug.ll

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Fix epilogue codegen to avoid leaving the stack pointer in an invalid state. Previously Thumb2 would restore sp from fp like this: mov sp, r7 sub, sp, #4 If an interrupt is taken after the 'mov' but before the 'sub', callee-saved registers might be clobbered by the interrupt handler. Instead, try restoring directly from sp: add sp, #4 Or, if necessary (with VLA, etc.) use a scratch register to compute sp and then restore it: sub.w r4, r7, #8 mov sp, r7 rdar://8465407 llvm-svn: 119977
2010-11-23 02:12:04 +08:00
; rdar://8465407
ARM & AArch64: make use of common cmpxchg idioms after expansion The C and C++ semantics for compare_exchange require it to return a bool indicating success. This gets mapped to LLVM IR which follows each cmpxchg with an icmp of the value loaded against the desired value. When lowered to ldxr/stxr loops, this extra comparison is redundant: its results are implicit in the control-flow of the function. This commit makes two changes: it replaces that icmp with appropriate PHI nodes, and then makes sure earlyCSE is called after expansion to actually make use of the opportunities revealed. I've also added -{arm,aarch64}-enable-atomic-tidy options, so that existing fragile tests aren't perturbed too much by the change. Many of them either rely on undef/unreachable too pervasively to be restored to something well-defined (particularly while making sure they test the same obscure assert from many years ago), or depend on a particular CFG shape, which is disrupted by SimplifyCFG. rdar://problem/16227836 llvm-svn: 209883
2014-05-30 18:09:59 +08:00
; RUN: llc < %s -mtriple=thumbv7-apple-ios -arm-atomic-cfg-tidy=0 | FileCheck %s
Fix epilogue codegen to avoid leaving the stack pointer in an invalid state. Previously Thumb2 would restore sp from fp like this: mov sp, r7 sub, sp, #4 If an interrupt is taken after the 'mov' but before the 'sub', callee-saved registers might be clobbered by the interrupt handler. Instead, try restoring directly from sp: add sp, #4 Or, if necessary (with VLA, etc.) use a scratch register to compute sp and then restore it: sub.w r4, r7, #8 mov sp, r7 rdar://8465407 llvm-svn: 119977
2010-11-23 02:12:04 +08:00
%struct.buf = type opaque
declare void @bar() nounwind optsize
Migrate function attribute "no-frame-pointer-elim" to "frame-pointer"="all" as cleanups after D56351
2019-12-25 07:52:21 +08:00
define void @foo() nounwind optsize "frame-pointer"="all" {
Mass update to CodeGen tests to use CHECK-LABEL for labels corresponding to function definitions for more informative error messages. No functionality change and all updated tests passed locally. This update was done with the following bash script: find test/CodeGen -name "*.ll" | \ while read NAME; do echo "$NAME" if ! grep -q "^; *RUN: *llc.*debug" $NAME; then TEMP=`mktemp -t temp` cp $NAME $TEMP sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \ while read FUNC; do sed -i '' "s/;\(.*\)\([A-Za-z0-9_-]*\):\( *\)$FUNC: *\$/;\1\2-LABEL:\3$FUNC:/g" $TEMP done sed -i '' "s/;\(.*\)-LABEL-LABEL:/;\1-LABEL:/" $TEMP sed -i '' "s/;\(.*\)-NEXT-LABEL:/;\1-NEXT:/" $TEMP sed -i '' "s/;\(.*\)-NOT-LABEL:/;\1-NOT:/" $TEMP sed -i '' "s/;\(.*\)-DAG-LABEL:/;\1-DAG:/" $TEMP mv $TEMP $NAME fi done llvm-svn: 186280
2013-07-14 14:24:09 +08:00
; CHECK-LABEL: foo:
Fix epilogue codegen to avoid leaving the stack pointer in an invalid state. Previously Thumb2 would restore sp from fp like this: mov sp, r7 sub, sp, #4 If an interrupt is taken after the 'mov' but before the 'sub', callee-saved registers might be clobbered by the interrupt handler. Instead, try restoring directly from sp: add sp, #4 Or, if necessary (with VLA, etc.) use a scratch register to compute sp and then restore it: sub.w r4, r7, #8 mov sp, r7 rdar://8465407 llvm-svn: 119977
2010-11-23 02:12:04 +08:00
; CHECK: push
[ARM] Call setBooleanContents(ZeroOrOneBooleanContent) The ARM backend should call setBooleanContents so that it can use known bits to make some optimizations. Review: D35821 Patch by Joel Galenson <jgalenson@google.com> llvm-svn: 311446
2017-08-22 19:02:37 +08:00
; CHECK: add r7, sp
Fix epilogue codegen to avoid leaving the stack pointer in an invalid state. Previously Thumb2 would restore sp from fp like this: mov sp, r7 sub, sp, #4 If an interrupt is taken after the 'mov' but before the 'sub', callee-saved registers might be clobbered by the interrupt handler. Instead, try restoring directly from sp: add sp, #4 Or, if necessary (with VLA, etc.) use a scratch register to compute sp and then restore it: sub.w r4, r7, #8 mov sp, r7 rdar://8465407 llvm-svn: 119977
2010-11-23 02:12:04 +08:00
; CHECK: sub sp, #4
entry:
%m.i = alloca %struct.buf*, align 4
br label %bb
bb:
br i1 undef, label %bb3, label %bb2
bb2:
call void @bar() nounwind optsize
br i1 undef, label %bb, label %bb3
bb3:
br i1 undef, label %return, label %bb
return:
Generalize MergeBlockIntoPredecessor. Replace uses of MergeBasicBlockIntoOnlyPred. Summary: Two utils methods have essentially the same functionality. This is an attempt to merge them into one. 1. lib/Transforms/Utils/Local.cpp : MergeBasicBlockIntoOnlyPred 2. lib/Transforms/Utils/BasicBlockUtils.cpp : MergeBlockIntoPredecessor Prior to the patch: 1. MergeBasicBlockIntoOnlyPred Updates either DomTree or DeferredDominance Moves all instructions from Pred to BB, deletes Pred Asserts BB has single predecessor If address was taken, replace the block address with constant 1 (?) 2. MergeBlockIntoPredecessor Updates DomTree, LoopInfo and MemoryDependenceResults Moves all instruction from BB to Pred, deletes BB Returns if doesn't have a single predecessor Returns if BB's address was taken After the patch: Method 2. MergeBlockIntoPredecessor is attempting to become the new default: Updates DomTree or DeferredDominance, and LoopInfo and MemoryDependenceResults Moves all instruction from BB to Pred, deletes BB Returns if doesn't have a single predecessor Returns if BB's address was taken Uses of MergeBasicBlockIntoOnlyPred that need to be replaced: 1. lib/Transforms/Scalar/LoopSimplifyCFG.cpp Updated in this patch. No challenges. 2. lib/CodeGen/CodeGenPrepare.cpp Updated in this patch. i. eliminateFallThrough is straightforward, but I added using a temporary array to avoid the iterator invalidation. ii. eliminateMostlyEmptyBlock(s) methods also now use a temporary array for blocks Some interesting aspects: - Since Pred is not deleted (BB is), the entry block does not need updating. - The entry block was being updated with the deleted block in eliminateMostlyEmptyBlock. Added assert to make obvious that BB=SinglePred. - isMergingEmptyBlockProfitable assumes BB is the one to be deleted. - eliminateMostlyEmptyBlock(BB) does not delete BB on one path, it deletes its unique predecessor instead. - adding some test owner as subscribers for the interesting tests modified: test/CodeGen/X86/avx-cmp.ll test/CodeGen/AMDGPU/nested-loop-conditions.ll test/CodeGen/AMDGPU/si-annotate-cf.ll test/CodeGen/X86/hoist-spill.ll test/CodeGen/X86/2006-11-17-IllegalMove.ll 3. lib/Transforms/Scalar/JumpThreading.cpp Not covered in this patch. It is the only use case using the DeferredDominance. I would defer to Brian Rzycki to make this replacement. Reviewers: chandlerc, spatel, davide, brzycki, bkramer, javed.absar Subscribers: qcolombet, sanjoy, nemanjai, nhaehnle, jlebar, tpr, kbarton, RKSimon, wmi, arsenm, llvm-commits Differential Revision: https://reviews.llvm.org/D48202 llvm-svn: 335183
2018-06-21 06:01:04 +08:00
; CHECK: %bb3
Fix epilogue codegen to avoid leaving the stack pointer in an invalid state. Previously Thumb2 would restore sp from fp like this: mov sp, r7 sub, sp, #4 If an interrupt is taken after the 'mov' but before the 'sub', callee-saved registers might be clobbered by the interrupt handler. Instead, try restoring directly from sp: add sp, #4 Or, if necessary (with VLA, etc.) use a scratch register to compute sp and then restore it: sub.w r4, r7, #8 mov sp, r7 rdar://8465407 llvm-svn: 119977
2010-11-23 02:12:04 +08:00
; 'mov sp, r7' would have left sp in an invalid state
; CHECK-NOT: mov sp, r7
; CHECK-NOT: sub, sp, #4
; CHECK: add sp, #4
ret void
}