Also add baseline tests to show effect of later patches.
There were a couple of regressions here that were never caught,
but my patch set that this is a preparation to will fix them.
This is the third attempt to land this patch.
Differential Revision: https://reviews.llvm.org/D61150
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363319 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts 363226 and 363227, both NFC intended
I swear I fixed the test case that is failing, and ran
the tests, but I will look into it again.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363229 91177308-0d34-0410-b5e6-96231b3b80d8
Also add baseline tests to show effect of later patches.
There were a couple of regressions here that were never caught,
but my patch set that this is a preparation to will fix them.
Differential Revision: https://reviews.llvm.org/D61150
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363226 91177308-0d34-0410-b5e6-96231b3b80d8
The old test was checking for a stupid subtract one that is a transform that
makes the code woorse.
The constant-islands-jump-table.ll test wants the code a specific way,
that makes sense, so I will submit code to fix that one.
Sorry that I really didn't know how to run the test suite before this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361733 91177308-0d34-0410-b5e6-96231b3b80d8
As it's causing some bot failures (and per request from kbarton).
This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358546 91177308-0d34-0410-b5e6-96231b3b80d8
This is no-functional-change-intended.
This is repackaging the functionality of D30333 (defer switch-to-lookup-tables) and
D35411 (defer folding unconditional branches) with pass parameters rather than a named
"latesimplifycfg" pass. Now that we have individual options to control the functionality,
we could decouple when these fire (but that's an independent patch if desired).
The next planned step would be to add another option bit to disable the sinking transform
mentioned in D38566. This should also make it clear that the new pass manager needs to
be updated to limit simplifycfg in the same way as the old pass manager.
Differential Revision: https://reviews.llvm.org/D38631
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316835 91177308-0d34-0410-b5e6-96231b3b80d8
The first variant contains all current transformations except
transforming switches into lookup tables. The second variant
contains all current transformations.
The switch-to-lookup-table conversion results in code that is more
difficult to analyze and optimize by other passes. Most importantly,
it can inhibit Dead Code Elimination. As such it is often beneficial to
only apply this transformation very late. A common example is inlining,
which can often result in range restrictions for the switch expression.
Changes in execution time according to LNT:
SingleSource/Benchmarks/Misc/fp-convert +3.03%
MultiSource/Benchmarks/ASC_Sequoia/CrystalMk/CrystalMk -11.20%
MultiSource/Benchmarks/Olden/perimeter/perimeter -10.43%
and a couple of smaller changes. For perimeter it also results 2.6%
a smaller binary.
Differential Revision: https://reviews.llvm.org/D30333
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298799 91177308-0d34-0410-b5e6-96231b3b80d8
Not all ConstantExprs can be represented by a global variable, for example most
pointer arithmetic other than addition of a constant, so we can't convert these
values from switch statements to lookup tables.
Differential Revision: https://reviews.llvm.org/D25550
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284379 91177308-0d34-0410-b5e6-96231b3b80d8
With the ROPI and RWPI relocation models we can't always have pointers
to global data or functions in constant data, so don't try to convert switches
into lookup tables if any value in the lookup table would require a relocation.
We can still safely emit lookup tables of other values, such as simple
constants.
Differential Revision: https://reviews.llvm.org/D24462
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283530 91177308-0d34-0410-b5e6-96231b3b80d8
ARM V6T2 has instructions for efficient count-leading/trailing-zeros, so this should be
considered a cheap operation (and therefore fair game for speculation) for any ARM V6T2
implementation.
The net result of allowing this speculation for the regression tests in this patch is
that we get this code:
ctlz:
clz r0, r0
bx lr
cttz:
rbit r0, r0
clz r0, r0
bx lr
Instead of:
ctlz:
cmp r0, #0
moveq r0, #32
clzne r0, r0
bx lr
cttz:
cmp r0, #0
moveq r0, #32
rbitne r0, r0
clzne r0, r0
bx lr
This will help solve a general speculation/despeculation problem noted in PR24818:
https://llvm.org/bugs/show_bug.cgi?id=24818
Differential Revision: http://reviews.llvm.org/D14469
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252639 91177308-0d34-0410-b5e6-96231b3b80d8
Shawn Landden