%shr = lshr i64 %key, 3
%0 = load i64* %val, align 8
%sub = add i64 %0, -1
%and = and i64 %sub, %shr
ret i64 %and
to:
%shr = lshr i64 %key, 3
%0 = load i64* %val, align 8
%sub = add i64 %0, 2305843009213693951
%and = and i64 %sub, %shr
ret i64 %and
The demanded bit optimization is actually a pessimization because add -1 would
be codegen'ed as a sub 1. Teach the demanded constant shrinking optimization
to check for negated constant to make sure it is actually reducing the width
of the constant.
rdar://11793464
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160101 91177308-0d34-0410-b5e6-96231b3b80d8
This patch removes ~70 lines in InstCombineLoadStoreAlloca.cpp and makes both functions a bit more aggressive than before :)
In theory, we can be more aggressive when removing an alloca than a malloc, because an alloca pointer should never escape, but we are not taking advantage of this anyway
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This means we can do cheap DSE for heap memory.
Nothing is done if the pointer excapes or has a load.
The churn in the tests is mostly due to objectsize, since we want to make sure we
don't delete the malloc call before evaluating the objectsize (otherwise it becomes -1/0)
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another mechanical change accomplished though the power of terrible Perl
scripts.
I have manually switched some "s to 's to make escaping simpler.
While I started this to fix tests that aren't run in all configurations,
the massive number of tests is due to a really frustrating fragility of
our testing infrastructure: things like 'grep -v', 'not grep', and
'expected failures' can mask broken tests all too easily.
Essentially, I'm deeply disturbed that I can change the testsuite so
radically without causing any change in results for most platforms. =/
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versions of Bash. In addition, I can back out the change to the lit
built-in shell test runner to support this.
This should fix the majority of fallout on Darwin, but I suspect there
will be a few straggling issues.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159544 91177308-0d34-0410-b5e6-96231b3b80d8
This was done through the aid of a terrible Perl creation. I will not
paste any of the horrors here. Suffice to say, it require multiple
staged rounds of replacements, state carried between, and a few
nested-construct-parsing hacks that I'm not proud of. It happens, by
luck, to be able to deal with all the TCL-quoting patterns in evidence
in the LLVM test suite.
If anyone is maintaining large out-of-tree test trees, feel free to poke
me and I'll send you the steps I used to convert things, as well as
answer any painful questions etc. IRC works best for this type of thing
I find.
Once converted, switch the LLVM lit config to use ShTests the same as
Clang. In addition to being able to delete large amounts of Python code
from 'lit', this will also simplify the entire test suite and some of
lit's architecture.
Finally, the test suite runs 33% faster on Linux now. ;]
For my 16-hardware-thread (2x 4-core xeon e5520): 36s -> 24s
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The original algorithm only used recursive pair fusion of equal-length
types. This is now extended to allow pairing of any types that share
the same underlying scalar type. Because we would still generally
prefer the 2^n-length types, those are formed first. Then a second
set of iterations form the non-2^n-length types.
Also, a call to SimplifyInstructionsInBlock has been added after each
pairing iteration. This takes care of DCE (and a few other things)
that make the following iterations execute somewhat faster. For the
same reason, some of the simple shuffle-combination cases are now
handled internally.
There is some additional refactoring work to be done, but I've had
many requests for this feature, so additional refactoring will come
soon in future commits (as will additional test cases).
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Original commit message:
If a constant or a function has linkonce_odr linkage and unnamed_addr, mark it
hidden. Being linkonce_odr guarantees that it is available in every dso that
needs it. Being a constant/function with unnamed_addr guarantees that the
copies don't have to be merged.
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before the expression root. Any existing operators that are changed to use one
of them needs to be moved between it and the expression root, and recursively
for the operators using that one. When I rewrote RewriteExprTree I accidentally
inverted the logic, resulting in the compacting going down from operators to
operands rather than up from operands to the operators using them, oops. Fix
this, resolving PR12963.
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// C - zext(bool) -> bool ? C - 1 : C
if (ZExtInst *ZI = dyn_cast<ZExtInst>(Op1))
if (ZI->getSrcTy()->isIntegerTy(1))
return SelectInst::Create(ZI->getOperand(0), SubOne(C), C);
This ends up forming sext i1 instructions that codegen to terrible code. e.g.
int blah(_Bool x, _Bool y) {
return (x - y) + 1;
}
=>
movzbl %dil, %eax
movzbl %sil, %ecx
shll $31, %ecx
sarl $31, %ecx
leal 1(%rax,%rcx), %eax
ret
Without the rule, llvm now generates:
movzbl %sil, %ecx
movzbl %dil, %eax
incl %eax
subl %ecx, %eax
ret
It also helps with ARM (and pretty much any target that doesn't have a sext i1 :-).
The transformation was done as part of Eli's r75531. He has given the ok to
remove it.
rdar://11748024
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merge all zero-sized alloca's into one, fixing c43204g from the Ada ACATS
conformance testsuite. What happened there was that a variable sized object
was being allocated on the stack, "alloca i8, i32 %size". It was then being
passed to another function, which tested that the address was not null (raising
an exception if it was) then manipulated %size bytes in it (load and/or store).
The optimizers cleverly managed to deduce that %size was zero (congratulations
to them, as it isn't at all obvious), which made the alloca zero size, causing
the optimizers to replace it with null, which then caused the check mentioned
above to fail, and the exception to be raised, wrongly. Note that no loads
and stores were actually being done to the alloca (the loop that does them is
executed %size times, i.e. is not executed), only the not-null address check.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159202 91177308-0d34-0410-b5e6-96231b3b80d8
The primary advantage is that loop optimizations will be applied in a
stable order. This helps debugging and unit test creation. It is also
a better overall implementation without pathologically bad performance
on deep functions.
On large functions (llvm-stress --size=200000 | opt -loops)
Before: 0.1263s
After: 0.0225s
On deep functions (after tweaking llvm-stress, thanks Nadav):
Before: 0.2281s
After: 0.0227s
See r158790 for more comments.
The loop tree is now consistently generated in forward order, but loop
passes are applied in reverse order over the program. If we have a
loop optimization that prefers forward order, that can easily be
achieved by adding a different type of LoopPassManager.
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- simplifycfg: invoke undef/null -> unreachable
- instcombine: invoke new -> invoke expect(0, 0) (an arbitrary NOOP intrinsic; only done if the allocated memory is unused, of course)
- verifier: allow invoke of intrinsics (to make the previous step work)
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hidden. Being linkonce_odr guarantees that it is available in every dso that
needs it. Being a constant/function with unnamed_addr guarantees that the
copies don't have to be merged.
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This fixes PR5997.
These transforms were disabled because codegen couldn't deal with other
uses of trunc(x). This is now handled by the peephole pass.
This causes no regressions on x86-64.
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- provide more extensive set of functions to detect library allocation functions (e.g., malloc, calloc, strdup, etc)
- provide an API to compute the size and offset of an object pointed by
Move a few clients (GVN, AA, instcombine, ...) to the new API.
This implementation is a lot more aggressive than each of the custom implementations being replaced.
Patch reviewed by Nick Lewycky and Chandler Carruth, thanks.
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The present implementation handles only TBAA and FP metadata, discarding everything else.
For debug metadata, the current behavior is maintained (the debug metadata associated with
one of the instructions will be kept, discarding that attached to the other).
This should address PR 13040.
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Dynamic GEPs created by SROA needed to insert extra "i32 0"
operands to index through structs and arrays to get to the
vector being indexed.
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linkonce linkage. For example, it is not valid to add unnamed_addr.
This also fixes a crash in g++.dg/opt/static5.C.
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example degenerate phi nodes and binops that use themselves in unreachable code.
Thanks to Charles Davis for the testcase that uncovered this can of worms.
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