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author | David Majnemer <david.majnemer@gmail.com> | 2013-04-11 20:13:52 +0000 |
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committer | David Majnemer <david.majnemer@gmail.com> | 2013-04-11 20:13:52 +0000 |
commit | bae6d527dffbe302a8130ceb40b4e82cf61414b1 (patch) | |
tree | 5431ea88369d3d75df3bae1d1b96193ef648477b /lib/Target/AArch64/Utils | |
parent | 59b11c415eb90861223477841913cf7d35b1a1a4 (diff) | |
download | external_llvm-bae6d527dffbe302a8130ceb40b4e82cf61414b1.zip external_llvm-bae6d527dffbe302a8130ceb40b4e82cf61414b1.tar.gz external_llvm-bae6d527dffbe302a8130ceb40b4e82cf61414b1.tar.bz2 |
Fix undefined behavior in AArch64
A64Imms::isLogicalImmBits and A64Imms::isLogicalImm will attempt to
execute shifts that perform undefined behavior. Instead of attempting
to perform the 64-bit rotation, treat it as a no-op.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179317 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/AArch64/Utils')
-rw-r--r-- | lib/Target/AArch64/Utils/AArch64BaseInfo.cpp | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/lib/Target/AArch64/Utils/AArch64BaseInfo.cpp b/lib/Target/AArch64/Utils/AArch64BaseInfo.cpp index 1678559..bedccb5 100644 --- a/lib/Target/AArch64/Utils/AArch64BaseInfo.cpp +++ b/lib/Target/AArch64/Utils/AArch64BaseInfo.cpp @@ -981,8 +981,11 @@ bool A64Imms::isLogicalImm(unsigned RegWidth, uint64_t Imm, uint32_t &Bits) { Rotation = RepeatWidth - Rotation; } - uint64_t ReplicatedOnes = (ReplicatedMask >> Rotation) - | ((ReplicatedMask << (RepeatWidth - Rotation)) & RepeatMask); + uint64_t ReplicatedOnes = ReplicatedMask; + if (Rotation != 0 && Rotation != 64) + ReplicatedOnes = (ReplicatedMask >> Rotation) + | ((ReplicatedMask << (RepeatWidth - Rotation)) & RepeatMask); + // Of course, they may not actually be ones, so we have to check that: if (!isMask_64(ReplicatedOnes)) continue; @@ -1051,13 +1054,14 @@ bool A64Imms::isLogicalImmBits(unsigned RegWidth, uint32_t Bits, int Rotation = (ImmR & (Width - 1)); uint64_t Mask = (1ULL << Num1s) - 1; uint64_t WidthMask = Width == 64 ? -1 : (1ULL << Width) - 1; - Mask = (Mask >> Rotation) - | ((Mask << (Width - Rotation)) & WidthMask); + if (Rotation != 0 && Rotation != 64) + Mask = (Mask >> Rotation) + | ((Mask << (Width - Rotation)) & WidthMask); - Imm = 0; - for (unsigned i = 0; i < RegWidth / Width; ++i) { - Imm |= Mask; + Imm = Mask; + for (unsigned i = 1; i < RegWidth / Width; ++i) { Mask <<= Width; + Imm |= Mask; } return true; |