f7087ea508
Reinstate the optimization from r151449 with a fix to not turn 'gep %x' into
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'gep null' when the icmp predicate is unsigned (or is signed without inbounds).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151467 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-26 02:09:49 +00:00
6fd3428afa
Roll these back to r151448 until I figure out how they're breaking
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MultiSource/Applications/lua.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151463 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-25 23:01:19 +00:00
1e4e1c768b
Teach instsimplify to be more aggressive when analyzing comparisons of pointers
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by using llvm::isIdentifiedObject. Also teach it to handle GEPs that have
the same base pointer and constant operands. Fixes PR11238!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151449 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-25 19:07:42 +00:00
8294eb5599
InstCombine: Don't transform a signed icmp of two GEPs into a signed compare of the indices.
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This transformation is not safe in some pathological cases (signed icmp of pointers should be an
extremely rare thing, but it's valid IR!). Add an explanatory comment.
Kudos to Duncan for pointing out this edge case (and not giving up explaining it until I finally got it).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151055 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-21 13:31:09 +00:00
117314009e
Test case for r150978.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150979 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-20 19:00:28 +00:00
9bb40853ee
InstCombine: When comparing two GEPs that were derived from the same base pointer but use different types, expand the offset calculation and to the compare on the offset if profitable.
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This came up in SmallVector code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150962 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-20 15:07:47 +00:00
04594aeffa
Add r149110 back with a fix for when the vector and the int have the same
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width.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149151 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-27 23:33:07 +00:00
41cedd740d
Revert r149110 and add a testcase that was crashing since that revision.
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Unfortunately I also had to disable constant-pool-sharing.ll the code it tests has been
updated to use the IL logic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149148 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-27 22:42:48 +00:00
f983da030e
enhance constant folding to be able to constant fold bitcast of
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ConstantVector's to integer type.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149110 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-27 01:44:03 +00:00
44aac553f6
FileCheck hygiene.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147580 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-05 00:43:34 +00:00
165695d261
Improved fix for abs(val) != 0 to check other similar case. Also fixed style issues and confusing comment
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145618 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-01 19:13:26 +00:00
dbaad16959
Removed use of grep from test and moved it to be with other icmp tests
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145570 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-01 04:35:26 +00:00
fc87cdc1f4
PR10267: Don't combine an equality compare with an AND into an inequality compare when the AND has more than one use.
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This can pessimize code, inequalities are generally more expensive.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134379 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-04 20:16:36 +00:00
e7fdcad2f2
InstCombine: Fold A-b == C --> b == A-C if A and C are constants.
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The backend already knew this trick.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132915 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-13 15:24:24 +00:00
ffd0ae64c4
InstCombine: Shrink ((zext X) & C1) == C2 to fold away the cast if the "zext" and the "and" have one use.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132897 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-12 22:48:00 +00:00
b6e7cd655c
PR9838: Fix transform introduced in r127064 to not trigger when only one side of the icmp is an exact shift.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130954 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-05 21:59:18 +00:00
325eeb1cd7
Transform: "icmp eq (trunc (lshr(X, cst1)), cst" to "icmp (and X, mask), cst"
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when X has multiple uses. This is useful for exposing secondary optimizations,
but the X86 backend isn't ready for this when X has a single use. For example,
this can disable load folding.
This is inching towards resolving PR6627.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130238 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-26 20:18:20 +00:00
7bff3e7c1b
Fix mistyped CHECK lines.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127366 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-09 22:07:31 +00:00
bf433e5f46
Tweak this test. We can analyze what happens and show that we still do the
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right thing, instead of merely being unable to analyze and the transform
doesn't occur.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127149 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-07 02:10:18 +00:00
c14bc77315
Add more analysis of the sign bit of an srem instruction. If the LHS is negative
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then the result could go either way. If it's provably positive then so is the
srem. Fixes PR9343 #7 !
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127146 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-07 01:50:10 +00:00
d01f50f42c
ConstantInt has some getters which return ConstantInt's or ConstantVector's of
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the value splatted into every element. Extend this to getTrue and getFalse which
by providing new overloads that take Types that are either i1 or <N x i1>. Use
it in InstCombine to add vector support to some code, fixing PR8469!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127116 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-06 03:36:19 +00:00
58bfcdbcf6
Thread comparisons over udiv/sdiv/ashr/lshr exact and lshr nuw/nsw whenever
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possible. This goes into instcombine and instsimplify because instsimplify
doesn't need to check hasOneUse since it returns (almost exclusively) constants.
This fixes PR9343 #4 #5 and #8 !
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127064 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-05 05:19:11 +00:00
9feda1730c
Try once again to optimize "icmp (srem X, Y), Y" by turning the comparison into
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true/false or "icmp slt/sge Y, 0".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127063 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-05 04:28:48 +00:00
786792784e
Fold "icmp pred (srem X, Y), Y" like we do for urem. Handle signed comparisons
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in the urem case, though not the other way around. This is enough to get #3 from
PR9343!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126991 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-04 10:06:52 +00:00
3dc7e49c70
srem doesn't actually have the same resulting sign as its numerator, you could
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also have a zero when numerator = denominator. Reverts parts of r126635 and
r126637.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126644 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-28 09:17:39 +00:00
b042f8e969
Teach InstCombine to fold "(shr exact X, Y) == 0" --> X == 0, fixing #1 from
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PR9343.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126643 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-28 08:31:40 +00:00
d8d1584c13
The sign of an srem instruction is the sign of its dividend (the first
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argument), regardless of the divisor. Teach instcombine about this and fix
test7 in PR9343!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126635 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-28 06:20:05 +00:00
39a7de72c8
Add some transforms of the kind X-Y>X -> 0>Y which are valid when there is no
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overflow. These subsume some existing equality transforms, so zap those.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125843 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-18 16:25:37 +00:00
a77243300b
Transform "A + B >= A + C" into "B >= C" if the adds do not wrap. Likewise for some
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variations (some of these were already present so I unified the code). Spotted by my
auto-simplifier as occurring a lot.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125734 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-17 07:46:37 +00:00
6cdf2ea98e
implement the first part of PR8882: when lowering an inbounds
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gep to explicit addressing, we know that none of the intermediate
computation overflows.
This could use review: it seems that the shifts certainly wouldn't
overflow, but could the intermediate adds overflow if there is a
negative index?
Previously the testcase would instcombine to:
define i1 @test(i64 %i) {
%p1.idx.mask = and i64 %i, 4611686018427387903
%cmp = icmp eq i64 %p1.idx.mask, 1000
ret i1 %cmp
}
now we get:
define i1 @test(i64 %i) {
%cmp = icmp eq i64 %i, 1000
ret i1 %cmp
}
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125271 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-10 07:11:16 +00:00
6bfd77e315
merge two tests.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125195 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-09 17:06:41 +00:00
da1c122da5
Fix a random missed optimization by making InstCombine more aggressive when determining which bits are demanded by
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a comparison against a constant.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123203 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11 00:36:45 +00:00
79b967bd9f
duncan's spider sense was right, I completely reversed the condition
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on this instcombine xform. This fixes a miscompilation of 403.gcc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119988 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-23 02:42:04 +00:00
75d8f599e7
optimize:
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void a(int x) { if (((1<<x)&8)==0) b(); }
into "x != 3", which occurs over 100 times in 403.gcc but in no
other program in llvm-test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119922 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-21 06:44:42 +00:00
0dd3549edc
Constant fold x == undef to undef.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107074 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-28 21:30:07 +00:00
c8e14b3d37
fix incorrect folding of icmp with undef, PR6481.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97659 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-03 19:46:03 +00:00
6304b0dd63
fix PR6195, a bug constant folding scalar -> vector compares.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94997 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-01 20:04:40 +00:00
3bf6815556
enhance x-(-A) -> x+A to preserve NUW/NSW.
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Use the presence of NSW/NUW to fold "icmp (x+cst), x" to a constant in
cases where it would otherwise be undefined behavior.
Surprisingly (to me at least), this triggers hundreds of the times in
a few benchmarks: lencode, ldecode, and 466.h264ref seem to *really*
like this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91812 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-21 04:04:05 +00:00
2799bafb98
Optimize all cases of "icmp (X+Cst), X" to something simpler. This triggers
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a bunch in lencode, ldecod, spass, 176.gcc, 252.eon, among others. It is
also the first part of PR5822
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91811 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-21 03:19:28 +00:00
6b57a797ab
convert to filecheck
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91810 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-21 03:11:05 +00:00
0036e3a469
simplify a transformation by making it more general.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83792 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-11 21:22:21 +00:00
3e054fe9ef
Use opt -S instead of piping bitcode output through llvm-dis.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81257 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-08 22:34:10 +00:00
b1e1e82c54
Change these tests to feed the assembly files to opt directly, instead
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of using llvm-as, now that opt supports this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81226 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-08 16:50:01 +00:00
9e17b632ec
fix PR4837, some bugs folding vector compares. These
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return a vector of i1, not i1 itself.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80761 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-02 05:12:37 +00:00
a80d668215
Implement rdar://6480391, extending of equality icmp's to avoid a truncation.
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I noticed this in the code compiled for a routine using std::map, which produced
this code:
%25 = tail call i32 @memcmp(i8* %24, i8* %23, i32 6) nounwind readonly
%.lobit.i = lshr i32 %25, 31 ; <i32> [#uses=1]
%tmp.i = trunc i32 %.lobit.i to i8 ; <i8> [#uses=1]
%toBool = icmp eq i8 %tmp.i, 0 ; <i1> [#uses=1]
br i1 %toBool, label %bb3, label %bb4
which compiled to:
call L_memcmp$stub
shrl $31, %eax
testb %al, %al
jne LBB1_11 ##
with this change, we compile it to:
call L_memcmp$stub
testl %eax, %eax
js LBB1_11
This triggers all the time in common code, with patters like this:
%169 = and i32 %ply, 1 ; <i32> [#uses=1]
%170 = trunc i32 %169 to i8 ; <i8> [#uses=1]
%toBool = icmp ne i8 %170, 0 ; <i1> [#uses=1]
%7 = lshr i32 %6, 24 ; <i32> [#uses=1]
%9 = trunc i32 %7 to i8 ; <i8> [#uses=1]
%10 = icmp ne i8 %9, 0 ; <i1> [#uses=1]
etc
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61985 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-09 07:47:06 +00:00
2b544beda3
For PR1319:
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Upgrade tests to work with new llvm.exp version of llvm_runtest.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36013 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-14 20:13:02 +00:00
12f591342f
sext of compares.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35892 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-11 06:57:54 +00:00
f6e166b386
new testcase
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35889 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-11 06:52:24 +00:00
