The attached patch unify the handle of shifts when the shift amount is
greater or equal the bit width.
Nowadays, LLVM evaluates shl(i32 X,32) to 0 in some places and to
undef in other places.
For compatibility purpose, this patch implements the gcc behavior.
This fix the miscompilation of the file ffmpeg/libavformat/mpeg.c.
Proposed behavior:
=== shl(X,N) =====
if (N<bitwidth(X)) result = X << N
if (N>=bitwidth(X)) result = 0;
=== Lshr(X,N) =====
if (N<bitwidth(X)) result = X >> N
if (N>=bitwidth(X)) result = 0;
=== Ashr(X,N) =====
if (N<bitwidth(X)) result = X >> N
if (N>=bitwidth(X) && X<0) result = -1;
if (N>=bitwidth(X) && X>=0) result = 0;
Lauro
? NightlyTestAccept.php
? NightlyTestAccept.php.1
? NightlyTestAccept.php.2
? build
? patch
? docs/patch
? lib/Target/ARM/patch
? projects/llvm-test/antigos.fail
? projects/llvm-test/novo.fail
? projects/llvm-test/patch
? projects/llvm-test/resultados.antigo
? projects/llvm-test/resultados.novo
? projects/llvm-test/MultiSource/Applications/SIBsim4/Output
? projects/llvm-test/MultiSource/Applications/minisat/Output
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/.dir
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gdevmem.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gdevs.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gp_unix.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.cbe
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.cbe.c
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.diff-cbe
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.diff-jit
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.diff-llc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.linked.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.linked.rbc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.llc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.llc.s
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.llvm
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.llvm.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.native
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.out-cbe
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.out-cbe.time
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.out-jit
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.out-jit.time
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.out-llc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.out-llc.time
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.out-nat
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gs.out-nat.time
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gschar.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gscolor.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gscoord.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gsdevice.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gsfile.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gsfont.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gsim2out.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gsimage.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gsline.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gsmain.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gsmatrix.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gsmisc.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gspaint.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gspath.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gspath2.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gsstate.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gstype1.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gxcache.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gxcolor.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gxdither.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gxdraw.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gxfill.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gxht.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gxpath.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gxpath2.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/gxstroke.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/ialloc.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/idebug.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/idict.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/iinit.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/iname.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/interp.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/iscan.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/iutil.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/stream.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/utrace.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zarith.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zarray.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zchar.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zcolor.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zcontrol.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zdevice.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zdict.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zfile.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zfont.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zgeneric.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zgstate.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zht.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zmath.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zmatrix.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zmisc.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zpacked.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zpaint.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zpath.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zpath2.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zrelbit.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zstack.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zstring.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/ztype.bc
? projects/llvm-test/MultiSource/Benchmarks/MallocBench/gs/Output/zvmem.bc
? projects/llvm-test/MultiSource/Benchmarks/MiBench/automotive-basicmath/Output
? projects/llvm-test/MultiSource/Benchmarks/MiBench/automotive-bitcount/Output
? projects/llvm-test/MultiSource/Benchmarks/MiBench/automotive-susan/Output
? projects/llvm-test/MultiSource/Benchmarks/MiBench/consumer-jpeg/Output
? projects/llvm-test/MultiSource/Benchmarks/MiBench/consumer-lame/Output
? projects/llvm-test/MultiSource/Benchmarks/MiBench/consumer-typeset/large.lout.ldx
? projects/llvm-test/MultiSource/Benchmarks/MiBench/consumer-typeset/lout.li
? projects/llvm-test/MultiSource/Benchmarks/MiBench/consumer-typeset/lout.lix
? projects/llvm-test/MultiSource/Benchmarks/MiBench/network-dijkstra/Output
? projects/llvm-test/MultiSource/Benchmarks/MiBench/network-patricia/Output
? projects/llvm-test/MultiSource/Benchmarks/MiBench/office-ispell/Output
? projects/llvm-test/MultiSource/Benchmarks/MiBench/office-stringsearch/Output
? projects/llvm-test/MultiSource/Benchmarks/MiBench/security-blowfish/Output
? projects/llvm-test/MultiSource/Benchmarks/MiBench/security-rijndael/Output
? projects/llvm-test/MultiSource/Benchmarks/MiBench/security-sha/Output
? projects/llvm-test/MultiSource/Benchmarks/MiBench/telecomm-CRC32/Output
? projects/llvm-test/MultiSource/Benchmarks/MiBench/telecomm-FFT/Output
? projects/llvm-test/MultiSource/Benchmarks/MiBench/telecomm-adpcm/Output
? projects/llvm-test/MultiSource/Benchmarks/MiBench/telecomm-gsm/Output
? projects/llvm-test/MultiSource/Benchmarks/tramp3d-v4/Output
? projects/llvm-test/SingleSource/Benchmarks/McGill/patch
? projects/llvm-test/SingleSource/UnitTests/Threads/Output
? test/CodeGen/ARM/a.out
? tools/bugpoint/patch
? utils/patch
Index: lib/Support/APInt.cpp
===================================================================
RCS file: /var/cvs/llvm/llvm/lib/Support/APInt.cpp,v
retrieving revision 1.86
diff -u -r1.86 APInt.cpp
--- lib/Support/APInt.cpp 19 May 2007 00:29:55 -0000 1.86
+++ lib/Support/APInt.cpp 12 Jun 2007 19:54:17 -0000
@@ -1053,32 +1053,27 @@
/// Arithmetic right-shift this APInt by shiftAmt.
/// @brief Arithmetic right-shift function.
APInt APInt::ashr(uint32_t shiftAmt) const {
- assert(shiftAmt <= BitWidth && "Invalid shift amount");
// Handle a degenerate case
if (shiftAmt == 0)
return *this;
- // Handle single word shifts with built-in ashr
- if (isSingleWord()) {
- if (shiftAmt == BitWidth)
- return APInt(BitWidth, 0); // undefined
- else {
- uint32_t SignBit = APINT_BITS_PER_WORD - BitWidth;
- return APInt(BitWidth,
- (((int64_t(VAL) << SignBit) >> SignBit) >> shiftAmt));
- }
- }
-
// If all the bits were shifted out, the result is, technically, undefined.
// We return -1 if it was negative, 0 otherwise. We check this early to avoid
// issues in the algorithm below.
- if (shiftAmt == BitWidth) {
+ if (shiftAmt >= BitWidth) {
if (isNegative())
return APInt(BitWidth, -1ULL);
else
return APInt(BitWidth, 0);
}
+ // Handle single word shifts with built-in ashr
+ if (isSingleWord()) {
+ uint32_t SignBit = APINT_BITS_PER_WORD - BitWidth;
+ return APInt(BitWidth,
+ (((int64_t(VAL) << SignBit) >> SignBit) >> shiftAmt));
+ }
+
// Create some space for the result.
uint64_t * val = new uint64_t[getNumWords()];
@@ -1136,24 +1131,20 @@
/// Logical right-shift this APInt by shiftAmt.
/// @brief Logical right-shift function.
APInt APInt::lshr(uint32_t shiftAmt) const {
- if (isSingleWord()) {
- if (shiftAmt == BitWidth)
- return APInt(BitWidth, 0);
- else
- return APInt(BitWidth, this->VAL >> shiftAmt);
- }
+ // If none of the bits are shifted out, the result is *this. This avoids
+ // issues with shifting byt he size of the integer type, which produces
+ // undefined results in the code below. This is also an optimization.
+ if (shiftAmt == 0)
+ return *this;
// If all the bits were shifted out, the result is 0. This avoids issues
// with shifting by the size of the integer type, which produces undefined
// results. We define these "undefined results" to always be 0.
- if (shiftAmt == BitWidth)
+ if (shiftAmt >= BitWidth)
return APInt(BitWidth, 0);
- // If none of the bits are shifted out, the result is *this. This avoids
- // issues with shifting byt he size of the integer type, which produces
- // undefined results in the code below. This is also an optimization.
- if (shiftAmt == 0)
- return *this;
+ if (isSingleWord())
+ return APInt(BitWidth, this->VAL >> shiftAmt);
// Create some space for the result.
uint64_t * val = new uint64_t[getNumWords()];
@@ -1198,24 +1189,20 @@
/// Left-shift this APInt by shiftAmt.
/// @brief Left-shift function.
APInt APInt::shl(uint32_t shiftAmt) const {
- assert(shiftAmt <= BitWidth && "Invalid shift amount");
- if (isSingleWord()) {
- if (shiftAmt == BitWidth)
- return APInt(BitWidth, 0); // avoid undefined shift results
- return APInt(BitWidth, VAL << shiftAmt);
- }
+ // If none of the bits are shifted out, the result is *this. This avoids a
+ // lshr by the words size in the loop below which can produce incorrect
+ // results. It also avoids the expensive computation below for a common case.
+ if (shiftAmt == 0)
+ return *this;
// If all the bits were shifted out, the result is 0. This avoids issues
// with shifting by the size of the integer type, which produces undefined
// results. We define these "undefined results" to always be 0.
- if (shiftAmt == BitWidth)
+ if (shiftAmt >= BitWidth)
return APInt(BitWidth, 0);
- // If none of the bits are shifted out, the result is *this. This avoids a
- // lshr by the words size in the loop below which can produce incorrect
- // results. It also avoids the expensive computation below for a common case.
- if (shiftAmt == 0)
- return *this;
+ if (isSingleWord())
+ return APInt(BitWidth, VAL << shiftAmt);
// Create some space for the result.
uint64_t * val = new uint64_t[getNumWords()];
Index: lib/VMCore/ConstantFold.cpp
===================================================================
RCS file: /var/cvs/llvm/llvm/lib/VMCore/ConstantFold.cpp,v
retrieving revision 1.150
diff -u -r1.150 ConstantFold.cpp
--- lib/VMCore/ConstantFold.cpp 26 Mar 2007 20:09:02 -0000 1.150
+++ lib/VMCore/ConstantFold.cpp 12 Jun 2007 19:54:18 -0000
@@ -631,26 +631,12 @@
case Instruction::Xor:
return ConstantInt::get(C1V ^ C2V);
case Instruction::Shl:
- if (uint32_t shiftAmt = C2V.getZExtValue())
- if (shiftAmt < C1V.getBitWidth())
- return ConstantInt::get(C1V.shl(shiftAmt));
- else
- return UndefValue::get(C1->getType()); // too big shift is undef
- return const_cast<ConstantInt*>(CI1); // Zero shift is identity
+ return ConstantInt::get(C1V.shl(C2V.getZExtValue()));
case Instruction::LShr:
- if (uint32_t shiftAmt = C2V.getZExtValue())
- if (shiftAmt < C1V.getBitWidth())
- return ConstantInt::get(C1V.lshr(shiftAmt));
- else
- return UndefValue::get(C1->getType()); // too big shift is undef
- return const_cast<ConstantInt*>(CI1); // Zero shift is identity
+ return ConstantInt::get(C1V.lshr(C2V.getZExtValue()));
case Instruction::AShr:
- if (uint32_t shiftAmt = C2V.getZExtValue())
- if (shiftAmt < C1V.getBitWidth())
- return ConstantInt::get(C1V.ashr(shiftAmt));
- else
- return UndefValue::get(C1->getType()); // too big shift is undef
- return const_cast<ConstantInt*>(CI1); // Zero shift is identity
+ return ConstantInt::get(C1V.ashr(C2V.getZExtValue()));
+
}
}
} else if (const ConstantFP *CFP1 = dyn_cast<ConstantFP>(C1)) {
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