This is a retry of 9397bdc67eb2 - that was reverted until
we had a clang warning in place to alert users about a
possible mistake in source. The warning was added with
ab982eace6e4.
This is noted as a missing clang warning in #54222,
but it is also a missing optimization opportunity.
Alive2 proofs:
https://alive2.llvm.org/ce/z/Q8drDqhttps://alive2.llvm.org/ce/z/pE6LRt
I don't see a single conversion for all predicates
using "getFCmpCode" logic, so other predicates are
left as a TODO item.
X (any pred) -X --> X (any pred) 0.0
This works with all FP values and preserves FMF.
Alive2 examples:
https://alive2.llvm.org/ce/z/dj6jhp
This can also create one of the patterns that we match as "fabs"
as shown in one of the test diffs.
This reverts commit 9397bdc67eb2b9eedc247a89bef01c2484b48b89.
This optimization is likely to surprise programmers as seen
in post-commit comments, so we should add a clang warning
first (that is proposed in D121306).
This is noted as a missing clang warning in #54222
(and we should still make that enhancement).
Alive2 proofs:
https://alive2.llvm.org/ce/z/Q8drDqhttps://alive2.llvm.org/ce/z/pE6LRt
I don't see a single conversion for all predicates
using "getFCmpCode" logic, so other predicates are
left as a TODO item.
As discussed in:
https://llvm.org/PR49179
...this pattern shows up in library code.
There are several potential generalizations as noted,
but we need to be careful that we get FP special-values
right, and it's not clear how much variation we should
expect to see from this exact idiom.
As it's causing some bot failures (and per request from kbarton).
This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.
llvm-svn: 358546
By morphing the instruction rather than deleting and creating a new one,
we retain fast-math-flags and potentially other metadata (profile info?).
llvm-svn: 346331
The sibling fold for 'oge' --> 'ord' was already here,
but this half was missing.
The result of fabs() must be positive or nan, so asking
if the result is negative or nan is the same as asking
if the result is nan.
This is another step towards fixing:
https://bugs.llvm.org/show_bug.cgi?id=39475
llvm-svn: 346321
This is another part of solving PR39475:
https://bugs.llvm.org/show_bug.cgi?id=39475
This might be enough to fix that particular issue, but as noted
with the FIXME, we're still dropping FMF on other folds around here.
llvm-svn: 346234
As stated in IEEE-754 and discussed in:
https://bugs.llvm.org/show_bug.cgi?id=38086
...the sign of zero does not affect any FP compare predicate.
Known regressions were fixed with:
rL346097 (D54001)
rL346143
The transform will help reduce pattern-matching complexity to solve:
https://bugs.llvm.org/show_bug.cgi?id=39475
...as well as improve CSE and codegen (a zero constant is almost always
easier to produce than 0x80..00).
llvm-svn: 346147
When C is not zero and infinites are not allowed (C / X) > 0 is a sign
test. Depending on the sign of C, the predicate must be swapped.
E.g.:
foo(double X) {
if ((-2.0 / X) <= 0) ...
}
=>
foo(double X) {
if (X >= 0) ...
}
Patch by: @marels (Martin Elshuber)
Differential Revision: https://reviews.llvm.org/D51942
llvm-svn: 343228
Using cstfp_pred_ty in the definition allows us to match vectors with undef elements.
This replicates the change for m_Not from D44076 / rL326823 and continues
towards making all pattern matchers allow undef elements in vectors.
llvm-svn: 329303
Summary:
See the two test cases.
; Can fold fcmp with undef on one side by choosing NaN for the undef
; Can fold fcmp with undef on both side
; fcmp u_pred undef, undef -> true
; fcmp o_pred undef, undef -> false
; because whatever you choose for the first undef
; you can choose NaN for the other undef
Reviewers: hfinkel, chandlerc, majnemer
Reviewed By: majnemer
Subscribers: majnemer, llvm-commits
Differential Revision: http://reviews.llvm.org/D7617
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231626
This update was done with the following bash script:
find test/Transforms -name "*.ll" | \
while read NAME; do
echo "$NAME"
if ! grep -q "^; *RUN: *llc" $NAME; then
TEMP=`mktemp -t temp`
cp $NAME $TEMP
sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \
while read FUNC; do
sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP
done
mv $TEMP $NAME
fi
done
llvm-svn: 186268
