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llvm-project/llvm/test/Transforms/TailCallElim/inf-recursion.ll

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[TailCallElim] Preserve DT and PDT Summary: Previously, in the NewPM pipeline, TailCallElim recalculates the DomTree when it modifies any instruction in the Function. For example, ``` CallInst *CI = dyn_cast<CallInst>(&I); ... CI->setTailCall(); Modified = true; ... if (!Modified || ...) return PreservedAnalyses::all(); ``` After applying this patch, the DomTree only recalculates if needed (plus an extra insertEdge() + an extra deleteEdge() call). When optimizing SQLite with `-passes="default<O3>"` pipeline of the newPM, the number of DomTree recalculation decreases by 6.2%, the number of nodes visited by DFS decreases by 2.9%. The time used by DomTree will decrease approximately 1%~2.5% after applying the patch. Statistics: ``` Before the patch: 23010 dom-tree-stats - Number of DomTree recalculations 489264 dom-tree-stats - Number of nodes visited by DFS -- DomTree After the patch: 21581 dom-tree-stats - Number of DomTree recalculations 475088 dom-tree-stats - Number of nodes visited by DFS -- DomTree ``` Reviewers: kuhar, dmgreen, brzycki, grosser, davide Reviewed By: kuhar, brzycki Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D49982 llvm-svn: 338954
2018-08-04 16:13:47 +08:00
; RUN: opt < %s -tailcallelim -verify-dom-info -S | FileCheck %s
Refine the detection of seemingly infinitely recursive calls where the callee is expected to be expanded to something else by codegen, so that normal infinitely recursive calls are still transformed. llvm-svn: 101468
2010-04-16 23:57:50 +08:00
Prevent tailcallelim from breaking "recursive" calls to builtins. llvm-svn: 41804
2007-09-11 04:58:55 +08:00
; Don't turn this into an infinite loop, this is probably the implementation
; of fabs and we expect the codegen to lower fabs.
Refine the detection of seemingly infinitely recursive calls where the callee is expected to be expanded to something else by codegen, so that normal infinitely recursive calls are still transformed. llvm-svn: 101468
2010-04-16 23:57:50 +08:00
; CHECK: @fabs(double %f)
; CHECK: call
; CHECK: ret
Prevent tailcallelim from breaking "recursive" calls to builtins. llvm-svn: 41804
2007-09-11 04:58:55 +08:00
define double @fabs(double %f) {
entry:
%tmp2 = call double @fabs( double %f ) ; <double> [#uses=1]
ret double %tmp2
}
Refine the detection of seemingly infinitely recursive calls where the callee is expected to be expanded to something else by codegen, so that normal infinitely recursive calls are still transformed. llvm-svn: 101468
2010-04-16 23:57:50 +08:00
; Do turn other calls into infinite loops though.
Catch more CHECK that can be converted to CHECK-LABEL in Transforms for easier debugging. No functionality change. This conversion was done with the following bash script: find test/Transforms -name "*.ll" | \ while read NAME; do echo "$NAME" if ! grep -q "^; *RUN: *llc" $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/;\(.*\)\([A-Za-z0-9_]*\):\( *\)define\([^@]*\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3define\4@$FUNC(/g" $TEMP done mv $TEMP $NAME fi done llvm-svn: 186269
2013-07-14 09:50:49 +08:00
; CHECK-LABEL: define double @foo(
Refine the detection of seemingly infinitely recursive calls where the callee is expected to be expanded to something else by codegen, so that normal infinitely recursive calls are still transformed. llvm-svn: 101468
2010-04-16 23:57:50 +08:00
; CHECK-NOT: call
; CHECK: }
define double @foo(double %f) {
%t= call double @foo(double %f)
ret double %t
}
Catch more CHECK that can be converted to CHECK-LABEL in Transforms for easier debugging. No functionality change. This conversion was done with the following bash script: find test/Transforms -name "*.ll" | \ while read NAME; do echo "$NAME" if ! grep -q "^; *RUN: *llc" $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/;\(.*\)\([A-Za-z0-9_]*\):\( *\)define\([^@]*\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3define\4@$FUNC(/g" $TEMP done mv $TEMP $NAME fi done llvm-svn: 186269
2013-07-14 09:50:49 +08:00
; CHECK-LABEL: define float @fabsf(
Refine the detection of seemingly infinitely recursive calls where the callee is expected to be expanded to something else by codegen, so that normal infinitely recursive calls are still transformed. llvm-svn: 101468
2010-04-16 23:57:50 +08:00
; CHECK-NOT: call
; CHECK: }
define float @fabsf(float %f) {
%t= call float @fabsf(float 2.0)
ret float %t
}
declare x86_fp80 @fabsl(x86_fp80 %f)
TRE: Just erase dead BBs and tweak the iteration loop not to increment the deleted BB iterator. Leaving empty blocks around just opens up a can of bugs like PR22704. Deleting them early also slightly simplifies code. Thanks to Sanjay for the IR test case. llvm-svn: 230856
2015-03-01 00:47:27 +08:00
; Don't crash while transforming a function with infinite recursion.
define i32 @PR22704(i1 %bool) {
entry:
br i1 %bool, label %t, label %f
t:
%call1 = call i32 @PR22704(i1 1)
br label %return
f:
%call = call i32 @PR22704(i1 1)
br label %return
return:
ret i32 0
; CHECK-LABEL: @PR22704(
; CHECK: %bool.tr = phi i1 [ %bool, %entry ], [ true, %t ], [ true, %f ]
; CHECK: br i1 %bool.tr, label %t, label %f
}