llvm-6502/test/Transforms/InstCombine
Andrea Di Biagio a34cab9be7 [InstCombine] Fix wrong folding of constant comparison involving ahsr and negative quantities (PR20945).
Example:
define i1 @foo(i32 %a) {
  %shr = ashr i32 -9, %a
  %cmp = icmp ne i32 %shr, -5
  ret i1 %cmp
}

Before this fix, the instruction combiner wrongly thought that %shr
could have never been equal to -5. Therefore, %cmp was always folded to 'true'.
However, when %a is equal to 1, then %cmp evaluates to 'false'. Therefore,
in this example, it is not valid to fold %cmp to 'true'.
The problem was only affecting the case where the comparison was between
negative quantities where one of the quantities was obtained from arithmetic
shift of a negative constant.

This patch fixes the problem with the wrong folding (fixes PR20945).
With this patch, the 'icmp' from the example is now simplified to a
comparison between %a and 1. This still allows us to get rid of the arithmetic
shift (%shr).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217950 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-17 11:32:31 +00:00
..
2002-03-11-InstCombineHang.ll
2002-05-14-SubFailure.ll
2002-08-02-CastTest.ll
2002-12-05-MissedConstProp.ll
2003-05-26-CastMiscompile.ll
2003-05-27-ConstExprCrash.ll
2003-06-05-BranchInvertInfLoop.ll
2003-07-21-ExternalConstant.ll
2003-08-12-AllocaNonNull.ll
2003-09-09-VolatileLoadElim.ll
2003-10-29-CallSiteResolve.ll
2003-11-03-VarargsCallBug.ll
2004-01-13-InstCombineInvokePHI.ll
2004-02-23-ShiftShiftOverflow.ll
2004-03-13-InstCombineInfLoop.ll
2004-04-04-InstCombineReplaceAllUsesWith.ll
2004-05-07-UnsizedCastLoad.ll
2004-07-27-ConstantExprMul.ll
2004-08-09-RemInfLoop.ll
2004-08-10-BoolSetCC.ll
2004-09-20-BadLoadCombine2.ll
2004-09-20-BadLoadCombine.ll
2004-09-28-BadShiftAndSetCC.ll
2004-11-22-Missed-and-fold.ll
2004-11-27-SetCCForCastLargerAndConstant.ll
2004-12-08-RemInfiniteLoop.ll
2005-03-04-ShiftOverflow.ll
2005-04-07-UDivSelectCrash.ll
2005-06-15-DivSelectCrash.ll
2005-06-15-ShiftSetCCCrash.ll
2005-06-16-RangeCrash.ll
2005-06-16-SetCCOrSetCCMiscompile.ll
2005-07-07-DeadPHILoop.ll
2006-02-13-DemandedMiscompile.ll
2006-02-28-Crash.ll
2006-03-30-ExtractElement.ll
2006-04-28-ShiftShiftLongLong.ll
2006-05-04-DemandedBitCrash.ll
2006-09-15-CastToBool.ll
2006-10-19-SignedToUnsignedCastAndConst-2.ll
2006-10-20-mask.ll
2006-10-26-VectorReassoc.ll
2006-11-10-ashr-miscompile.ll
2006-12-01-BadFPVectorXform.ll
2006-12-05-fp-to-int-ext.ll
2006-12-08-Phi-ICmp-Op-Fold.ll
2006-12-08-Select-ICmp.ll
2006-12-15-Range-Test.ll
2006-12-23-Select-Cmp-Cmp.ll
2007-01-13-ExtCompareMiscompile.ll
2007-01-14-FcmpSelf.ll
2007-01-18-VectorInfLoop.ll
2007-01-27-AndICmp.ll
2007-02-01-LoadSinkAlloca.ll
2007-02-07-PointerCast.ll
2007-02-23-PhiFoldInfLoop.ll
2007-03-13-CompareMerge.ll
2007-03-19-BadTruncChangePR1261.ll
2007-03-21-SignedRangeTest.ll
2007-03-25-BadShiftMask.ll
2007-03-25-DoubleShift.ll
2007-03-26-BadShiftMask.ll
2007-04-08-SingleEltVectorCrash.ll
2007-05-10-icmp-or.ll
2007-05-14-Crash.ll
2007-05-18-CastFoldBug.ll
2007-06-06-AshrSignBit.ll
2007-06-21-DivCompareMiscomp.ll
2007-08-02-InfiniteLoop.ll
2007-09-10-AliasConstFold.ll Use "weak alias" instead of "alias weak" 2014-07-30 22:51:54 +00:00
2007-09-17-AliasConstFold2.ll Use "weak alias" instead of "alias weak" 2014-07-30 22:51:54 +00:00
2007-10-10-EliminateMemCpy.ll
2007-10-12-Crash.ll
2007-10-28-stacksave.ll
2007-10-31-RangeCrash.ll
2007-10-31-StringCrash.ll
2007-11-07-OpaqueAlignCrash.ll
2007-11-15-CompareMiscomp.ll
2007-11-22-IcmpCrash.ll
2007-11-25-CompatibleAttributes.ll
2007-12-10-ConstFoldCompare.ll
2007-12-12-GEPScale.ll
2007-12-16-AsmNoUnwind.ll
2007-12-18-AddSelCmpSub.ll
2007-12-28-IcmpSub2.ll
2008-01-06-BitCastAttributes.ll
2008-01-06-CastCrash.ll
2008-01-06-VoidCast.ll
2008-01-13-AndCmpCmp.ll
2008-01-13-NoBitCastAttributes.ll
2008-01-14-VarArgTrampoline.ll
2008-01-21-MismatchedCastAndCompare.ll
2008-01-21-MulTrunc.ll
2008-01-27-FloatSelect.ll
2008-01-29-AddICmp.ll
2008-02-13-MulURem.ll
2008-02-16-SDivOverflow2.ll
2008-02-16-SDivOverflow.ll
2008-02-23-MulSub.ll
2008-02-28-OrFCmpCrash.ll
2008-03-13-IntToPtr.ll
2008-04-22-ByValBitcast.ll
2008-04-28-VolatileStore.ll
2008-04-29-VolatileLoadDontMerge.ll
2008-04-29-VolatileLoadMerge.ll
2008-05-08-LiveStoreDelete.ll
2008-05-08-StrLenSink.ll
2008-05-09-SinkOfInvoke.ll
2008-05-17-InfLoop.ll
2008-05-18-FoldIntToPtr.ll
2008-05-22-IDivVector.ll
2008-05-22-NegValVector.ll
2008-05-23-CompareFold.ll
2008-05-31-AddBool.ll
2008-05-31-Bools.ll
2008-06-05-ashr-crash.ll
2008-06-08-ICmpPHI.ll
2008-06-13-InfiniteLoopStore.ll
2008-06-13-ReadOnlyCallStore.ll
2008-06-19-UncondLoad.ll
2008-06-21-CompareMiscomp.ll
2008-06-24-StackRestore.ll
2008-07-08-AndICmp.ll
2008-07-08-ShiftOneAndOne.ll
2008-07-08-SubAnd.ll
2008-07-08-VolatileLoadMerge.ll
2008-07-09-SubAndError.ll
2008-07-10-CastSextBool.ll
2008-07-10-ICmpBinOp.ll
2008-07-11-RemAnd.ll
2008-07-13-DivZero.ll
2008-07-16-fsub.ll
2008-07-16-sse2_storel_dq.ll
2008-08-05-And.ll
2008-08-17-ICmpXorSignbit.ll
2008-09-02-VectorCrash.ll
2008-09-29-FoldingOr.ll
2008-10-11-DivCompareFold.ll
2008-10-23-ConstFoldWithoutMask.ll
2008-11-01-SRemDemandedBits.ll
2008-11-08-FCmp.ll
2008-11-20-DivMulRem.ll
2008-11-27-IDivVector.ll
2008-11-27-MultiplyIntVec.ll
2008-11-27-UDivNegative.ll
2008-12-17-SRemNegConstVec.ll
2009-01-05-i128-crash.ll
2009-01-08-AlignAlloca.ll
2009-01-16-PointerAddrSpace.ll
2009-01-19-fmod-constant-float-specials.ll
2009-01-19-fmod-constant-float.ll
2009-01-24-EmptyStruct.ll
2009-01-31-InfIterate.ll
2009-01-31-Pressure.ll
2009-02-04-FPBitcast.ll
2009-02-11-NotInitialized.ll
2009-02-20-InstCombine-SROA.ll
2009-02-21-LoadCST.ll
2009-02-25-CrashZeroSizeArray.ll
2009-03-18-vector-ashr-crash.ll
2009-03-20-AShrOverShift.ll
2009-03-24-InfLoop.ll
2009-04-07-MulPromoteToI96.ll
2009-05-23-FCmpToICmp.ll
2009-06-11-StoreAddrSpace.ll
2009-06-16-SRemDemandedBits.ll
2009-07-02-MaskedIntVector.ll
2009-12-17-CmpSelectNull.ll
2010-01-28-NegativeSRem.ll
2010-03-03-ExtElim.ll IR: Fold away compares between GV GEPs and GVs 2014-07-04 22:05:26 +00:00
2010-05-30-memcpy-Struct.ll
2010-11-01-lshr-mask.ll
2010-11-21-SizeZeroTypeGEP.ll
2010-11-23-Distributed.ll
2011-02-14-InfLoop.ll
2011-03-08-SRemMinusOneBadOpt.ll
2011-05-02-VectorBoolean.ll
2011-05-13-InBoundsGEP.ll
2011-05-28-swapmulsub.ll
2011-06-13-nsw-alloca.ll
2011-09-03-Trampoline.ll
2011-10-07-AlignPromotion.ll
2012-3-15-or-xor-constant.ll
2012-6-7-vselect-bitcast.ll
2012-01-11-OpaqueBitcastCrash.ll
2012-02-13-FCmp.ll
2012-02-28-ICmp.ll
2012-03-10-InstCombine.ll
2012-04-23-Neon-Intrinsics.ll
2012-04-24-vselect.ll
2012-04-30-SRem.ll
2012-05-27-Negative-Shift-Crash.ll
2012-05-28-select-hang.ll
2012-06-06-LoadOfPHIs.ll
2012-07-25-LoadPart.ll
2012-07-30-addrsp-bitcast.ll
2012-08-28-udiv_ashl.ll
2012-09-17-ZeroSizedAlloca.ll
2012-09-24-MemcpyFromGlobalCrash.ll
2012-10-25-vector-of-pointers.ll
2012-12-14-simp-vgep.ll
2013-03-05-Combine-BitcastTy-Into-Alloca.ll
abs_abs.ll
abs-1.ll
add2.ll InstCombine: Combine (add (and %a, %b) (or %a, %b)) to (add %a, %b) 2014-08-11 22:32:02 +00:00
add3.ll
add-shrink.ll
add-sitofp.ll
add.ll
addnegneg.ll
AddOverFlow.ll
addrspacecast.ll
adjust-for-sminmax.ll
align-2d-gep.ll
align-addr.ll
align-attr.ll Make use of the align parameter attribute for all pointer arguments 2014-07-22 16:58:55 +00:00
align-external.ll
alloca.ll
and2.ll InstCombine: Try harder to combine icmp instructions 2014-08-30 06:18:20 +00:00
and-compare.ll
and-fcmp.ll
and-not-or.ll
and-or-and.ll
and-or-not.ll
and-or.ll
and-xor-merge.ll
and-xor-or.ll
and.ll
apint-add1.ll
apint-add2.ll
apint-and1.ll
apint-and2.ll
apint-and-compare.ll
apint-and-or-and.ll
apint-and-xor-merge.ll
apint-call-cast-target.ll
apint-cast-and-cast.ll
apint-cast-cast-to-and.ll
apint-cast.ll
apint-div1.ll
apint-div2.ll
apint-mul1.ll
apint-mul2.ll
apint-not.ll
apint-or1.ll
apint-or2.ll
apint-rem1.ll
apint-rem2.ll
apint-select.ll
apint-shift-simplify.ll
apint-shift.ll
apint-shl-trunc.ll
apint-sub.ll
apint-xor1.ll
apint-xor2.ll
apint-zext1.ll
apint-zext2.ll
assume2.ll Add additional patterns for @llvm.assume in ValueTracking 2014-09-07 19:21:07 +00:00
assume-loop-align.ll Make use of @llvm.assume in ValueTracking (computeKnownBits, etc.) 2014-09-07 18:57:58 +00:00
assume.ll Check for all known bits on ret in InstCombine 2014-09-07 21:28:34 +00:00
atomic.ll
badmalloc.ll
binop-cast.ll
bit-checks.ll
bit-tracking.ll
bitcast-alias-function.ll
bitcast-bigendian.ll
bitcast-sext-vector.ll
bitcast-store.ll
bitcast-vec-canon.ll
bitcast-vec-uniform.ll
bitcast-vector-fold.ll
bitcast.ll
bitcount.ll
bittest.ll
blend_x86.ll
bswap-fold.ll
bswap.ll
call2.ll
call-cast-target-inalloca.ll
call-cast-target.ll
call-intrinsics.ll
call.ll
canonicalize_branch.ll
cast_ptr.ll
cast-call-combine.ll
cast-mul-select.ll
cast-set.ll
cast.ll InstCombine: Don't unconditionally preserve 'nuw' when shrinking constants 2014-08-22 17:11:04 +00:00
ceil.ll
compare-signs.ll
constant-expr-datalayout.ll
constant-fold-address-space-pointer.ll
constant-fold-compare.ll
constant-fold-gep.ll
constant-fold-math.ll
copysign.ll
cos-1.ll
cos-2.ll
CPP_min_max.ll
crash.ll
dce-iterate.ll
deadcode.ll
debug-line.ll
debuginfo.ll
descale-zero.ll InstCombine: Fix a crash in Descale for multiply-by-zero 2014-07-10 17:13:27 +00:00
devirt.ll
disable-simplify-libcalls.ll
distribute.ll
div-shift-crash.ll
div-shift.ll
div.ll InstCombine: Combine mul with div. 2014-08-16 08:55:06 +00:00
double-float-shrink-1.ll
double-float-shrink-2.ll
enforce-known-alignment.ll
err-rep-cold.ll
exact.ll
exp2-1.ll
exp2-2.ll
ExtractCast.ll
extractvalue.ll
fast-math.ll
fcmp-select.ll
fcmp-special.ll
fcmp.ll
fdiv.ll
ffs-1.ll
float-shrink-compare.ll
fmul.ll
fneg-ext.ll
fold-bin-operand.ll
fold-calls.ll
fold-fops-into-selects.ll
fold-phi.ll
fold-sqrt-sqrtf.ll
fold-vector-select.ll
fold-vector-zero.ll
fp-ret-bitcast.ll
fpcast.ll
fpextend_x86.ll
fpextend.ll
fprintf-1.ll
fputs-1.ll
fsub.ll
fwrite-1.ll
gep-addrspace.ll
gepgep.ll
gepphigep.ll
getelementptr.ll Revert "Revert two GEP-related InstCombine commits" 2014-09-01 21:10:02 +00:00
hoist_instr.ll
icmp-logical.ll
icmp-shr.ll [InstCombine] Fix wrong folding of constant comparison involving ahsr and negative quantities (PR20945). 2014-09-17 11:32:31 +00:00
icmp.ll InstSimplify: Move a transform from InstCombine to InstSimplify 2014-08-28 03:34:28 +00:00
idioms.ll
insert-extract-shuffle.ll
IntPtrCast.ll
intrinsics.ll InstCombine: Strength reduce sadd.with.overflow into a regular nsw add if we can prove that it cannot overflow. 2014-07-04 10:22:21 +00:00
invariant.ll
invoke.ll
isascii-1.ll
isdigit-1.ll
JavaCompare.ll
known_align.ll
LandingPadClauses.ll
load3.ll
load-addrspace-cast.ll
load-cmp.ll
load-select.ll
load.ll Convert test to FileCheck. 2014-07-15 00:07:27 +00:00
loadstore-alignment.ll Teach computeKnownBits to look through addrspacecast. 2014-07-15 01:55:03 +00:00
logical-select.ll
lshr-phi.ll
malloc-free-delete.ll
memcmp-1.ll InstCombine: Annotate sub with nsw when we prove it's safe 2014-08-19 23:36:30 +00:00
memcmp-2.ll
memcpy_chk-1.ll
memcpy_chk-2.ll
memcpy-1.ll
memcpy-2.ll
memcpy-from-global.ll
memcpy-to-load.ll
memcpy.ll
memmove_chk-1.ll
memmove_chk-2.ll
memmove-1.ll
memmove-2.ll
memmove.ll
memset2.ll
memset_chk-1.ll
memset_chk-2.ll
memset-1.ll
memset-2.ll
memset.ll
merge-icmp.ll
mul-masked-bits.ll
mul.ll
multi-size-address-space-pointer.ll
multi-use-or.ll
narrow.ll
neon-intrinsics.ll
no-negzero.ll
not-fcmp.ll
not.ll
nothrow.ll
nsw.ll
obfuscated_splat.ll
objsize-64.ll
objsize-address-space.ll Use "weak alias" instead of "alias weak" 2014-07-30 22:51:54 +00:00
objsize.ll Use "weak alias" instead of "alias weak" 2014-07-30 22:51:54 +00:00
odr-linkage.ll
onehot_merge.ll
or-fcmp.ll
or-to-xor.ll
or-xor.ll InstCombine: Fold ((A | B) & C1) ^ (B & C2) -> (A & C1) ^ B if C1^C2=-1 2014-08-21 05:14:48 +00:00
or.ll New InstCombine pattern: (icmp ult/ule (A + C1), C3) | (icmp ult/ule (A + C2), C3) to (icmp ult/ule ((A & ~(C1 ^ C2)) + max(C1, C2)), C3) under certain condition 2014-08-20 22:55:40 +00:00
osx-names.ll
overflow-mul.ll
overflow.ll
OverlappingInsertvalues.ll
phi-merge-gep.ll
phi-select-constexpr.ll
phi.ll
pow-1.ll
pow-2.ll
pow-3.ll
pr2645-0.ll
pr2645-1.ll
pr2996.ll
pr8547.ll
pr12251.ll
pr12338.ll
pr17827.ll
pr19420.ll
pr20059.ll removed duplicate testcase 2014-07-09 17:49:58 +00:00
pr20079.ll IR: Fold away compares between GV GEPs and GVs 2014-07-04 22:05:26 +00:00
PR7357.ll
preserve-sminmax.ll
printf-1.ll
printf-2.ll
ptr-int-cast.ll
puts-1.ll
r600-intrinsics.ll
README.txt
rem.ll
round.ll
sdiv-1.ll
sdiv-2.ll
select-2.ll
select-crash.ll
select-extractelement.ll
select-load-call.ll
select-select.ll
select.ll
set.ll
setcc-strength-reduce.ll
sext.ll
shift-sra.ll
shift.ll
shufflemask-undef.ll
shufflevec-constant.ll
sign-test-and-or.ll
signed-comparison.ll
signext.ll
simplify-demanded-bits-pointer.ll
simplify-libcalls.ll
sincospi.ll
sink_instruction.ll
sitofp.ll
sprintf-1.ll
sqrt.ll
srem1.ll
srem-simplify-bug.ll
srem.ll
stack-overalign.ll
stacksaverestore.ll
store.ll
stpcpy_chk-1.ll
stpcpy_chk-2.ll
stpcpy-1.ll
stpcpy-2.ll
strcat-1.ll
strcat-2.ll
strcat-3.ll
strchr-1.ll
strchr-2.ll
strcmp-1.ll InstCombine: Annotate sub with nsw when we prove it's safe 2014-08-19 23:36:30 +00:00
strcmp-2.ll
strcpy_chk-1.ll
strcpy_chk-2.ll
strcpy_chk-64.ll
strcpy-1.ll
strcpy-2.ll
strcspn-1.ll
strcspn-2.ll
strlen-1.ll
strlen-2.ll
strncat-1.ll
strncat-2.ll
strncat-3.ll
strncmp-1.ll InstCombine: Annotate sub with nsw when we prove it's safe 2014-08-19 23:36:30 +00:00
strncmp-2.ll
strncpy_chk-1.ll
strncpy_chk-2.ll
strncpy-1.ll
strncpy-2.ll
strpbrk-1.ll
strpbrk-2.ll
strrchr-1.ll
strrchr-2.ll
strspn-1.ll
strstr-1.ll
strstr-2.ll
strto-1.ll
struct-assign-tbaa.ll
sub-xor.ll InstCombine: Annotate sub with nsw when we prove it's safe 2014-08-19 23:36:30 +00:00
sub.ll InstCombine: sub nsw %x, C -> add nsw %x, -C if C isn't INT_MIN 2014-08-22 16:41:23 +00:00
toascii-1.ll
trunc.ll
udiv_select_to_select_shift.ll
udiv-simplify-bug-0.ll
udiv-simplify-bug-1.ll
udivrem-change-width.ll
urem-simplify-bug.ll
urem.ll
vec_demanded_elts.ll
vec_extract_2elts.ll
vec_extract_elt.ll
vec_extract_var_elt.ll
vec_insertelt.ll
vec_narrow.ll
vec_phi_extract.ll
vec_sext.ll
vec_shuffle.ll
vector_gep1.ll
vector_gep2.ll
vector-casts.ll
vector-mul.ll
vector-srem.ll
vector-type.ll
volatile_store.ll
weak-symbols.ll
win-math.ll
x86-crc32-demanded.ll
xor2.ll [InstCombine] Remove redundant test case. 2014-09-16 08:50:10 +00:00
xor-undef.ll
xor.ll
zero-point-zero-add.ll
zeroext-and-reduce.ll
zext-bool-add-sub.ll
zext-fold.ll
zext-or-icmp.ll
zext.ll

This directory contains test cases for the instcombine transformation.  The
dated tests are actual bug tests, whereas the named tests are used to test
for features that the this pass should be capable of performing.