to generate signed ICMP instructions to replace the FCMP. This would violate
the following:
define i1 @test1(i32 %val) {
%1 = uitofp i32 %val to double
%2 = fcmp ole double %1, 0.000000e+00
ret i1 %2
}
would be transformed into:
define i1 @test1(i32 %val) {
%1 = icmp slt i33 %val, 1
ret i1 %1
}
which is obviously wrong. This patch modifes InstCombiner::FoldFCmp_IntToFP_Cst
to handle when the LHS comes from UIToFP.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58929 91177308-0d34-0410-b5e6-96231b3b80d8
to find opportunities for store-to-load forwarding or load CSE,
in the same way that visitStore scans back to do DSE. Also, define
a new helper function for testing whether the addresses of two
memory accesses are known to have the same value, and use it in
both visitStore and visitLoad.
These two changes allow instcombine to eliminate loads in code
produced by front-ends that frequently emit obviously redundant
addressing for memory references.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57608 91177308-0d34-0410-b5e6-96231b3b80d8
- Renumber fcmp predicates to match their icmp counterparts.
- Try swapping operands to expose more optimization opportunities.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57513 91177308-0d34-0410-b5e6-96231b3b80d8
shifting and masking inside a bswap expr. This allows it to handle
the cases from PR2842, which involve the intermediate 'or'
expressions being shifted, not just the input value.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57095 91177308-0d34-0410-b5e6-96231b3b80d8
- Recognize expressions like "x > -1 ? x : 0" as min/max and turn them
into expressions like "x < 0 ? 0 : x", which is easily recognizable
as a min/max operation.
- Refrain from folding expression like "y/2 < 1" to "y < 2" when the
comparison is being used as part of a min or max idiom, like
"y/2 < 1 ? 1 : y/2". In that case, the division has another use, so
folding doesn't eliminate it, and obfuscates the min/max, making it
harder to recognize as a min/max operation.
These benefit ScalarEvolution, CodeGen, and anything else that wants to
recognize integer min and max.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56246 91177308-0d34-0410-b5e6-96231b3b80d8
getelementptr indices, inserting an explicit cast if necessary.
This helps expose the sign-extension operation to other optimizations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56133 91177308-0d34-0410-b5e6-96231b3b80d8
users, and teach it about shufflevector instructions.
Also, fix a subtle bug in SimplifyDemandedVectorElts'
insertelement code.
This is a patch that was originally written by Eli Friedman,
with some fixes and cleanup by me.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55995 91177308-0d34-0410-b5e6-96231b3b80d8
be folded. Instead, fail to fold the entire vector.
We could also return a vector with some elements folded and some not. If anyone
thinks that's a better approach, please speak up!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55689 91177308-0d34-0410-b5e6-96231b3b80d8
can have a non-negative result; for example, -16%16 is 0. Also,
clarify the related comments. This fixes PR2670.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54767 91177308-0d34-0410-b5e6-96231b3b80d8
do for scalars. Patch contributed by Nicolas Capens
This also generalizes the previous xforms to work on long double, now that
isExactlyValue works for long double.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54653 91177308-0d34-0410-b5e6-96231b3b80d8
was using the algorithm for folding unsigned comparisons which is
completely wrong. This has been broken since the signless types change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53444 91177308-0d34-0410-b5e6-96231b3b80d8
This cause a regression in InstCombine/JavaCompare, which was doing the right
thing on accident. To handle the missed case, generalize the comparisons based
on masked bits a little bit to handle comparisons against the max value. For
example, we can now xform (slt i32 (and X, 4), 4) -> (setne i32 (and X, 4), 4)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53443 91177308-0d34-0410-b5e6-96231b3b80d8
