[llvm-branch-commits] [llvm-branch] r323737 - Merging r323331:
Hans Wennborg via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Tue Jan 30 01:48:43 PST 2018
Author: hans
Date: Tue Jan 30 01:48:42 2018
New Revision: 323737
URL: http://llvm.org/viewvc/llvm-project?rev=323737&view=rev
Log:
Merging r323331:
------------------------------------------------------------------------
r323331 | spatel | 2018-01-24 16:20:37 +0100 (Wed, 24 Jan 2018) | 21 lines
[ValueTracking] add recursion depth param to matchSelectPattern
We're getting bug reports:
https://bugs.llvm.org/show_bug.cgi?id=35807
https://bugs.llvm.org/show_bug.cgi?id=35840
https://bugs.llvm.org/show_bug.cgi?id=36045
...where we blow up the stack in value tracking because other passes are sending
in selects that have an operand that is itself the select.
We don't currently have a reliable way to avoid analyzing dead code that may take
non-standard forms, so bail out when things go too far.
This mimics the recursion depth limitations in other parts of value tracking.
Unfortunately, this pushes the underlying problems for other passes (jump-threading,
simplifycfg, correlated-propagation) into hiding. If someone wants to uncover those
again, the first draft of this patch on Phab would do that (it would assert rather
than bail out).
Differential Revision: https://reviews.llvm.org/D42442
------------------------------------------------------------------------
Added:
llvm/branches/release_60/test/Analysis/ValueTracking/select-pattern.ll
- copied unchanged from r323331, llvm/trunk/test/Analysis/ValueTracking/select-pattern.ll
Modified:
llvm/branches/release_60/ (props changed)
llvm/branches/release_60/include/llvm/Analysis/ValueTracking.h
llvm/branches/release_60/lib/Analysis/ValueTracking.cpp
Propchange: llvm/branches/release_60/
------------------------------------------------------------------------------
--- svn:mergeinfo (original)
+++ svn:mergeinfo Tue Jan 30 01:48:42 2018
@@ -1,3 +1,3 @@
/llvm/branches/Apple/Pertwee:110850,110961
/llvm/branches/type-system-rewrite:133420-134817
-/llvm/trunk:155241,321751,321789,321791,321806,321862,321870,321872,321878,321980,321991,321993-321994,322003,322053,322056,322103,322106,322108,322123,322131,322223,322272,322313,322372,322473,322623,322644,322724,322767,322875,322878-322879,322900,322904-322905,322973,322993,323034,323190,323307,323369,323371,323384
+/llvm/trunk:155241,321751,321789,321791,321806,321862,321870,321872,321878,321980,321991,321993-321994,322003,322053,322056,322103,322106,322108,322123,322131,322223,322272,322313,322372,322473,322623,322644,322724,322767,322875,322878-322879,322900,322904-322905,322973,322993,323034,323190,323307,323331,323369,323371,323384
Modified: llvm/branches/release_60/include/llvm/Analysis/ValueTracking.h
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_60/include/llvm/Analysis/ValueTracking.h?rev=323737&r1=323736&r2=323737&view=diff
==============================================================================
--- llvm/branches/release_60/include/llvm/Analysis/ValueTracking.h (original)
+++ llvm/branches/release_60/include/llvm/Analysis/ValueTracking.h Tue Jan 30 01:48:42 2018
@@ -508,7 +508,8 @@ class Value;
/// -> LHS = %a, RHS = i32 4, *CastOp = Instruction::SExt
///
SelectPatternResult matchSelectPattern(Value *V, Value *&LHS, Value *&RHS,
- Instruction::CastOps *CastOp = nullptr);
+ Instruction::CastOps *CastOp = nullptr,
+ unsigned Depth = 0);
inline SelectPatternResult
matchSelectPattern(const Value *V, const Value *&LHS, const Value *&RHS,
Instruction::CastOps *CastOp = nullptr) {
Modified: llvm/branches/release_60/lib/Analysis/ValueTracking.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_60/lib/Analysis/ValueTracking.cpp?rev=323737&r1=323736&r2=323737&view=diff
==============================================================================
--- llvm/branches/release_60/lib/Analysis/ValueTracking.cpp (original)
+++ llvm/branches/release_60/lib/Analysis/ValueTracking.cpp Tue Jan 30 01:48:42 2018
@@ -4165,17 +4165,18 @@ static SelectPatternResult matchClamp(Cm
/// a < c ? min(a,b) : min(b,c) ==> min(min(a,b),min(b,c))
static SelectPatternResult matchMinMaxOfMinMax(CmpInst::Predicate Pred,
Value *CmpLHS, Value *CmpRHS,
- Value *TrueVal, Value *FalseVal) {
+ Value *TVal, Value *FVal,
+ unsigned Depth) {
// TODO: Allow FP min/max with nnan/nsz.
assert(CmpInst::isIntPredicate(Pred) && "Expected integer comparison");
Value *A, *B;
- SelectPatternResult L = matchSelectPattern(TrueVal, A, B);
+ SelectPatternResult L = matchSelectPattern(TVal, A, B, nullptr, Depth + 1);
if (!SelectPatternResult::isMinOrMax(L.Flavor))
return {SPF_UNKNOWN, SPNB_NA, false};
Value *C, *D;
- SelectPatternResult R = matchSelectPattern(FalseVal, C, D);
+ SelectPatternResult R = matchSelectPattern(FVal, C, D, nullptr, Depth + 1);
if (L.Flavor != R.Flavor)
return {SPF_UNKNOWN, SPNB_NA, false};
@@ -4240,7 +4241,8 @@ static SelectPatternResult matchMinMaxOf
static SelectPatternResult matchMinMax(CmpInst::Predicate Pred,
Value *CmpLHS, Value *CmpRHS,
Value *TrueVal, Value *FalseVal,
- Value *&LHS, Value *&RHS) {
+ Value *&LHS, Value *&RHS,
+ unsigned Depth) {
// Assume success. If there's no match, callers should not use these anyway.
LHS = TrueVal;
RHS = FalseVal;
@@ -4249,7 +4251,7 @@ static SelectPatternResult matchMinMax(C
if (SPR.Flavor != SelectPatternFlavor::SPF_UNKNOWN)
return SPR;
- SPR = matchMinMaxOfMinMax(Pred, CmpLHS, CmpRHS, TrueVal, FalseVal);
+ SPR = matchMinMaxOfMinMax(Pred, CmpLHS, CmpRHS, TrueVal, FalseVal, Depth);
if (SPR.Flavor != SelectPatternFlavor::SPF_UNKNOWN)
return SPR;
@@ -4313,7 +4315,8 @@ static SelectPatternResult matchSelectPa
FastMathFlags FMF,
Value *CmpLHS, Value *CmpRHS,
Value *TrueVal, Value *FalseVal,
- Value *&LHS, Value *&RHS) {
+ Value *&LHS, Value *&RHS,
+ unsigned Depth) {
LHS = CmpLHS;
RHS = CmpRHS;
@@ -4429,7 +4432,7 @@ static SelectPatternResult matchSelectPa
}
if (CmpInst::isIntPredicate(Pred))
- return matchMinMax(Pred, CmpLHS, CmpRHS, TrueVal, FalseVal, LHS, RHS);
+ return matchMinMax(Pred, CmpLHS, CmpRHS, TrueVal, FalseVal, LHS, RHS, Depth);
// According to (IEEE 754-2008 5.3.1), minNum(0.0, -0.0) and similar
// may return either -0.0 or 0.0, so fcmp/select pair has stricter
@@ -4550,7 +4553,11 @@ static Value *lookThroughCast(CmpInst *C
}
SelectPatternResult llvm::matchSelectPattern(Value *V, Value *&LHS, Value *&RHS,
- Instruction::CastOps *CastOp) {
+ Instruction::CastOps *CastOp,
+ unsigned Depth) {
+ if (Depth >= MaxDepth)
+ return {SPF_UNKNOWN, SPNB_NA, false};
+
SelectInst *SI = dyn_cast<SelectInst>(V);
if (!SI) return {SPF_UNKNOWN, SPNB_NA, false};
@@ -4579,7 +4586,7 @@ SelectPatternResult llvm::matchSelectPat
FMF.setNoSignedZeros();
return ::matchSelectPattern(Pred, FMF, CmpLHS, CmpRHS,
cast<CastInst>(TrueVal)->getOperand(0), C,
- LHS, RHS);
+ LHS, RHS, Depth);
}
if (Value *C = lookThroughCast(CmpI, FalseVal, TrueVal, CastOp)) {
// If this is a potential fmin/fmax with a cast to integer, then ignore
@@ -4588,11 +4595,11 @@ SelectPatternResult llvm::matchSelectPat
FMF.setNoSignedZeros();
return ::matchSelectPattern(Pred, FMF, CmpLHS, CmpRHS,
C, cast<CastInst>(FalseVal)->getOperand(0),
- LHS, RHS);
+ LHS, RHS, Depth);
}
}
return ::matchSelectPattern(Pred, FMF, CmpLHS, CmpRHS, TrueVal, FalseVal,
- LHS, RHS);
+ LHS, RHS, Depth);
}
/// Return true if "icmp Pred LHS RHS" is always true.
More information about the llvm-branch-commits
mailing list