Commit Graph

30 Commits

Author SHA1 Message Date
Sanjay Patel 2204520e49 [PatternMatch] define m_FNeg using m_FSub
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
2018-04-05 15:36:55 +00:00
Sanjay Patel 2eaa2a43f8 [InstCombine] add vector and vector undef tests for FP folds; NFC
llvm-svn: 329294
2018-04-05 15:07:35 +00:00
Sanjay Patel 81b3b10a95 [InstCombine] allow more fmul folds with 'reassoc'
The tests marked with 'FIXME' require loosening the check
in SimplifyAssociativeOrCommutative() to optimize completely;
that's still checking isFast() in Instruction::isAssociative().

llvm-svn: 329121
2018-04-03 22:19:19 +00:00
Sanjay Patel 4fd4fd610c [InstCombine] distribute fmul over fadd/fsub
This replaces a large chunk of code that was looking for compound
patterns that include these sub-patterns. Existing tests ensure that
all of the previous examples are still folded as expected.

We still need to loosen the FMF check.

llvm-svn: 328502
2018-03-26 15:03:57 +00:00
Sanjay Patel 2455fef497 [InstCombine] check uses before creating instructions for fmul distribution
As the tests show, we could create extra instructions without any obvious benefit.

llvm-svn: 328498
2018-03-26 14:25:43 +00:00
Sanjay Patel 1d0832d9a3 [InstCombine] move/add tests for fmul distribution; NFC
There are at least 3 problems:
1. We're distributing across large patterns, but fail to do that for the minimal patterns.
2. We're not checking uses, so we may create more instructions than we eliminate.
3. We should be able to do these transforms with less than full 'fast' fmuls.

llvm-svn: 328152
2018-03-21 21:28:19 +00:00
Sanjay Patel 204edeca56 [InstCombine] fix fmul reassociation to avoid creating an extra fdiv
This was supposed to be an NFC refactoring that will eventually allow
eliminating the isFast() predicate, but there's a rare possibility
that we would pessimize the code as shown in the test case because
we failed to check 'hasOneUse()' properly. This version also removes
an inefficiency of the old code; we would look for: 
(X * C) * C1 --> X * (C * C1)
...but that pattern is always handled by 
SimplifyAssociativeOrCommutative().

llvm-svn: 327404
2018-03-13 14:46:32 +00:00
Sanjay Patel a71f95404f [InstCombine] add test to show fmul transform creates extra fdiv; NFC
Also, move fmul reassociation tests to the same file as other fmul transforms.

llvm-svn: 327342
2018-03-12 23:10:08 +00:00
Sanjay Patel 2fd0acf05a [InstCombine] partly fix FMF for fmul+log2 fold
The code was checking that all of the instructions in the 
sequence are 'fast', but that's not necessary. The final 
multiply is all that we need to check (tests adjusted). 
The fmul doesn't need to be fully 'fast' either, but that 
can be another patch.

llvm-svn: 326608
2018-03-02 20:32:46 +00:00
Sanjay Patel bb7228703a [InstCombine] add tests for rL169025; NFC
This narrow fold was added with no motivation or test cases 
a bit over 5 years ago. Removing a constant operand is a 
good canonicalization? We should handle Y*2.0 too then?

llvm-svn: 326606
2018-03-02 19:26:13 +00:00
Sanjay Patel d0cdb2f861 [InstCombine] allow fmul fold with less than 'fast'
This is a retry of r326502 with updates to the reassociate 
test file that I missed the first time.

@test15_reassoc in the supposed -reassociate test file 
(except that it tests 2 other passes too...) shows that
there's no clear responsiblity for reassociation transforms.

Instcombine now gets that case, but only because the
constant values are identical. Otherwise, it would still
miss that pattern. 

Reassociate doesn't get that case because it hasn't been 
updated to use less than 'fast' FMF.

llvm-svn: 326513
2018-03-02 00:14:51 +00:00
Sanjay Patel eb5d046890 revert r326502: [InstCombine] allow fmul fold with less than 'fast'
I forgot that I added tests for 'reassoc' to -reassociate, but
suprisingly that file calls -instcombine too, so it is affected.
I'll update that file and try again.

llvm-svn: 326510
2018-03-01 23:39:24 +00:00
Sanjay Patel 7373ae5c9a [InstCombine] allow fmul fold with less than 'fast'
llvm-svn: 326502
2018-03-01 22:53:47 +00:00
Sanjay Patel 3fd43a843b [InstCombine] move/add tests for fmul reassociation; NFC
This transform may be out-of-scope for instcombine, 
but this is only documenting the current behavior.

llvm-svn: 326442
2018-03-01 15:30:44 +00:00
Sanjay Patel eaf5a120ed [InstCombine] simplify code for X * -1.0 --> -X; NFC
I've added random FMF to one of the tests to show those are propagated.

llvm-svn: 326377
2018-02-28 22:30:04 +00:00
Sanjay Patel db53d1847b [InstSimplify] sqrt(X) * sqrt(X) --> X
This was misplaced in InstCombine. We can loosen the FMF as a follow-up step.

llvm-svn: 325965
2018-02-23 22:20:13 +00:00
Sanjay Patel 92b7371113 [InstCombine] add fmul multi-use test; NFC
Also, rename tests to make their intent clearer.

llvm-svn: 325785
2018-02-22 14:27:16 +00:00
Sanjay Patel 9befaeb582 [InstCombine] add some random FMF to tests so we know it's not dropped; NFC
llvm-svn: 325734
2018-02-21 22:48:28 +00:00
Simon Pilgrim 5f022d278b [InstCombine] Regenerate FMUL/FMA combine tests with update_test_checks.py
llvm-svn: 320922
2017-12-16 17:18:15 +00:00
Matt Arsenault 56c079f393 InstCombine: fabs(x) * fabs(x) -> x * x
llvm-svn: 259295
2016-01-30 05:02:00 +00:00
David Blaikie a79ac14fa6 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

llvm-svn: 230794
2015-02-27 21:17:42 +00:00
Sanjay Patel 13a657819b Remove unused function attribute params.
llvm-svn: 218909
2014-10-02 21:12:04 +00:00
Sanjay Patel 12d1ce5408 Optimize square root squared (PR21126).
When unsafe-fp-math is enabled, we can turn sqrt(X) * sqrt(X) into X.

This can happen in the real world when calculating x ** 3/2. This occurs
in test-suite/SingleSource/Benchmarks/BenchmarkGame/n-body.c.

Differential Revision: http://reviews.llvm.org/D5584

llvm-svn: 218906
2014-10-02 21:10:54 +00:00
Owen Anderson 1664dc8973 Fix all the remaining lost-fast-math-flags bugs I've been able to find. The most important of these are cases in the generic logic for combining BinaryOperators.
This logic hadn't been updated to handle FastMathFlags, and it took me a while to detect it because it doesn't show up in a simple search for CreateFAdd.

llvm-svn: 199629
2014-01-20 07:44:53 +00:00
Benjamin Kramer fea9ac99b0 InstCombine: Make the (fmul X, -1.0) -> (fsub -0.0, X) transform handle vectors too.
PR18532.

llvm-svn: 199553
2014-01-18 16:43:14 +00:00
Owen Anderson e8537fc7e0 Fix a bug in InstCombine where we failed to preserve fast math flags when optimizing an FMUL expression.
llvm-svn: 199424
2014-01-16 20:59:41 +00:00
Owen Anderson f74cfe031f Teach InstCombine that (fmul X, -1.0) can be simplified to (fneg X), which LLVM expresses as (fsub -0.0, X).
llvm-svn: 199420
2014-01-16 20:36:42 +00:00
Joey Gouly d51a35c6a0 Fix a bug in InstCombine where it attempted to cast a Value* to an Instruction*
when it was actually a Constant*.

There are quite a few other casts to Instruction that might have the same problem,
but this is the only one I have a test case for.

llvm-svn: 191668
2013-09-30 14:18:35 +00:00
Stephen Lin c1c7a1309c Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.
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
2013-07-14 01:42:54 +00:00
Shuxin Yang e822745202 1. Hoist minus sign as high as possible in an attempt to reveal
some optimization opportunities (in the enclosing supper-expressions).

   rule 1. (-0.0 - X ) * Y => -0.0 - (X * Y)
     if expression "-0.0 - X" has only one reference.

   rule 2. (0.0 - X ) * Y => -0.0 - (X * Y)
     if expression "0.0 - X" has only one reference, and
        the instruction is marked "noSignedZero".

2. Eliminate negation (The compiler was already able to handle these
    opt if the 0.0s are replaced with -0.0.)

   rule 3: (0.0 - X) * (0.0 - Y) => X * Y
   rule 4: (0.0 - X) * C => X * -C
   if the expr is flagged "noSignedZero".

3. 
  Rule 5: (X*Y) * X => (X*X) * Y
   if X!=Y and the expression is flagged with "UnsafeAlgebra".

   The purpose of this transformation is two-fold:
    a) to form a power expression (of X).
    b) potentially shorten the critical path: After transformation, the
       latency of the instruction Y is amortized by the expression of X*X,
       and therefore Y is in a "less critical" position compared to what it
      was before the transformation. 

4. Remove the InstCombine code about simplifiying "X * select".
   
   The reasons are following:
    a) The "select" is somewhat architecture-dependent, therefore the
       higher level optimizers are not able to precisely predict if
       the simplification really yields any performance improvement
       or not.

    b) The "select" operator is bit complicate, and tends to obscure
       optimization opportunities. It is btter to keep it as low as
       possible in expr tree, and let CodeGen to tackle the optimization.

llvm-svn: 172551
2013-01-15 21:09:32 +00:00