Remove a use of getLowBitsSet that caused the mask used for replacement of
shl/lshr pairs with an AND instruction to be computed incorrectly. Its not
clear exactly why this is the case. This solves the disappearing shifts
problem, but it doesn't fix Regression/C/2003-05-21-UnionBitFields. It
seems there is more going on.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35342 91177308-0d34-0410-b5e6-96231b3b80d8
* Don't assume shift amounts are <= 64 bits
* Avoid creating an extra APInt in SubOne and AddOne by using -- and ++
* Add another use of getLowBitsSet
* Convert a series of if statements to a switch
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35339 91177308-0d34-0410-b5e6-96231b3b80d8
using the facilities of APInt. While this duplicates a tiny fraction of
the constant folding code, it also makes the code easier to read and
avoids large ConstantExpr overhead for simple, known computations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35335 91177308-0d34-0410-b5e6-96231b3b80d8
2. Use isStrictlyPositive() instead of isPositive() in two places where
they need APInt value > 0 not only >=0.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35333 91177308-0d34-0410-b5e6-96231b3b80d8
* Convert the last use of a uint64_t that should have been an APInt.
* Change ComputeMaskedBits to have a const reference argument for the Mask
so that recursions don't cause unneeded temporaries. This causes temps
to be needed in other places (where the mask has to change) but this
change optimizes for the recursion which is more frequent.
* Remove two instances of &ing a Mask with getAllOnesValue. Its not
needed any more because APInt is accurate in its bit computations.
* Start using the getLowBitsSet and getHighBits set methods on APInt
instead of shifting. This makes it more clear in the code what is
going on.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35321 91177308-0d34-0410-b5e6-96231b3b80d8
Convert some calls to ConstantInt::getZExtValue() into getValue() and
use APInt facilities in the subsequent computations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35294 91177308-0d34-0410-b5e6-96231b3b80d8
* APIntify visitAdd and visitSelectInst
* Remove unused uint64_t versions of utility functions that have been
replaced with APInt versions.
This completes most of the changes for APIntification of InstCombine. This
passes llvm-test and llvm/test/Transforms/InstCombine/APInt.
Patch by Zhou Sheng.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35287 91177308-0d34-0410-b5e6-96231b3b80d8
* Re-enable the APInt version of MaskedValueIsZero.
* APIntify the Comput{Un}SignedMinMaxValuesFromKnownBits functions
* APIntify visitICmpInst.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35270 91177308-0d34-0410-b5e6-96231b3b80d8
Analyze GEPs. If the indices are all zero, transfer whether the pointer is
known to be not null through the GEP.
Add a few more cases for xor and shift instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35257 91177308-0d34-0410-b5e6-96231b3b80d8
* Fix some indentation and comments in InsertRangeTest
* Add an "IsSigned" parameter to AddWithOverflow and make it handle signed
additions. Also, APIntify this function so it works with any bitwidth.
* For the icmp pred ([us]div %X, C1), C2 transforms, exit early if the
div instruction's RHS is zero.
* Finally, for icmp pred (sdiv %X, C1), -C2, fix an off-by-one error. The
HiBound needs to be incremented in order to get the range test correct.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35247 91177308-0d34-0410-b5e6-96231b3b80d8
Add new micro-optimizations.
Add icmp predicate snuggling. Given %x ULT 4, "icmp ugt %x, 2" becomes
"icmp eq %x, 3". This doesn't apply in any non-trivial cases yet due to missing
support for NE values in ValueRanges.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35119 91177308-0d34-0410-b5e6-96231b3b80d8
"APInt::getAllOnesValue(ShiftAmt).zextOrCopy(BitWidth)",
to handle ShiftAmt == BitWidth situation, use zextOrCopy() instead of
zext().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35080 91177308-0d34-0410-b5e6-96231b3b80d8
1. Replace getSignedMinValue() with getSignBit() for better code readability.
2. Replace APIntOps::shl() with operator<<= for convenience.
3. Make APInt construction more effective.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35060 91177308-0d34-0410-b5e6-96231b3b80d8
Provide an APIntified version of MaskedValueIsZero. This will (temporarily)
cause a "defined but not used" message from the compiler. It will be used
in the next patch in this series.
Patch by Sheng Zhou.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35019 91177308-0d34-0410-b5e6-96231b3b80d8
Add a new ComputeMaskedBits function that is APIntified. We'll slowly
convert things over to use this version. When its all done, we'll remove
the existing version.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35018 91177308-0d34-0410-b5e6-96231b3b80d8
scalarrepl things down to elements, but mem2reg can't promote elements that
are memset/memcpy'd. Until then, the code is disabled "0 &&".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34924 91177308-0d34-0410-b5e6-96231b3b80d8
would scan the entire loop body, then scan all users of instructions in the
loop, looking for users outside the loop. Now, since we know that the
loop is in LCSSA form, we know that any users outside the loop will be LCSSA
phi nodes. Just scan them.
This speeds up indvars significantly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34898 91177308-0d34-0410-b5e6-96231b3b80d8
the order that instcombine processed instructions in the testcase. The end
result is that instcombine finished with:
define i16 @test1(i16 %a) {
%tmp = zext i16 %a to i32 ; <i32> [#uses=2]
%tmp21 = lshr i32 %tmp, 8 ; <i32> [#uses=1]
%tmp5 = shl i32 %tmp, 8 ; <i32> [#uses=1]
%tmp.upgrd.32 = or i32 %tmp21, %tmp5 ; <i32> [#uses=1]
%tmp.upgrd.3 = trunc i32 %tmp.upgrd.32 to i16 ; <i16> [#uses=1]
ret i16 %tmp.upgrd.3
}
which can't get matched as a bswap.
This patch makes instcombine more sophisticated about removing truncating
casts, allowing it to turn this into:
define i16 @test2(i16 %a) {
%tmp211 = lshr i16 %a, 8
%tmp52 = shl i16 %a, 8
%tmp.upgrd.323 = or i16 %tmp211, %tmp52
ret i16 %tmp.upgrd.323
}
which then matches as bswap. This fixes bswap.ll and implements
InstCombine/cast2.ll:test[12]. This also implements cast elimination of
add/sub.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34870 91177308-0d34-0410-b5e6-96231b3b80d8
a value from the worklist required scanning the entire worklist to remove all
entries. We now use a combination map+vector to prevent duplicates from
happening and prevent the scan. This speeds up instcombine on a large file
from the llvm-gcc bootstrap from 189.7s to 4.84s in a debug build and from
5.04s to 1.37s in a release build.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34848 91177308-0d34-0410-b5e6-96231b3b80d8
First round of ConstantRange changes. This makes all CR constructors use
only APInt and not use ConstantInt. Clients are adjusted accordingly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34756 91177308-0d34-0410-b5e6-96231b3b80d8
