to work out (in a very simplistic way) which function
arguments (pointer arguments only) are only dereferenced
and so do not escape. Mark such arguments 'nocapture'.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61525 91177308-0d34-0410-b5e6-96231b3b80d8
and select instructions doesn't buy anything here
except extra complexity: the only difference in
the entire testsuite was that a readonly function
became readnone in MiBench/consumer-typeset. Add
a comment about this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61478 91177308-0d34-0410-b5e6-96231b3b80d8
constants, since doing so is irrelevant for aliasing
purposes. While this doesn't increase the total number
of functions marked readonly or readnone in MultiSource/
Applications (3089), it does result in 12 functions being
marked readnone rather than readonly.
Before:
readnone: 820
readonly: 2269
After:
readnone: 832
readonly: 2257
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61469 91177308-0d34-0410-b5e6-96231b3b80d8
other SPEC breakage. I'll be reverting all recent
changes shortly, this checking is mostly so this
change doesn't get lost.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61402 91177308-0d34-0410-b5e6-96231b3b80d8
my last patch to this file.
The issue there was that all uses of an IV inside a loop
are actually references to Base[IV*2], and there was one
use outside that was the same but LSR didn't see the base
or the scaling because it didn't recurse into uses outside
the loop; thus, it used base+IV*scale mode inside the loop
instead of pulling base out of the loop. This was extra bad
because register pressure later forced both base and IV into
memory. Doing that recursion, at least enough
to figure out addressing modes, is a good idea in general;
the change in AddUsersIfInteresting does this. However,
there were side effects....
It is also possible for recursing outside the loop to
introduce another IV where there was only 1 before (if
the refs inside are not scaled and the ref outside is).
I don't think this is a common case, but it's in the testsuite.
It is right to be very aggressive about getting rid of
such introduced IVs (CheckForIVReuse and the handling of
nonzero RewriteFactor in StrengthReduceStridedIVUsers).
In the testcase in question the new IV produced this way
has both a nonconstant stride and a nonzero base, neither
of which was handled before. And when inserting
new code that feeds into a PHI, it's right to put such
code at the original location rather than in the PHI's
immediate predecessor(s) when the original location is outside
the loop (a case that couldn't happen before)
(RewriteInstructionToUseNewBase); better to avoid making
multiple copies of it in this case.
Also, the mechanism for keeping SCEV's corresponding to GEP's
no longer works, as the GEP might change after its SCEV
is remembered, invalidating the SCEV, and we might get a bad
SCEV value when looking up the GEP again for a later loop.
This also couldn't happen before, as we weren't recursing
into GEP's outside the loop.
I owe some testcases for this, want to get it in for nightly runs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61362 91177308-0d34-0410-b5e6-96231b3b80d8
- Use SplitBlockPredecessors to factor out common predecessors of the critical edge destination. This is disabled for now due to some regressions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61248 91177308-0d34-0410-b5e6-96231b3b80d8
my last patch to this file.
The issue there was that all uses of an IV inside a loop
are actually references to Base[IV*2], and there was one
use outside that was the same but LSR didn't see the base
or the scaling because it didn't recurse into uses outside
the loop; thus, it used base+IV*scale mode inside the loop
instead of pulling base out of the loop. This was extra bad
because register pressure later forced both base and IV into
memory. Doing that recursion, at least enough
to figure out addressing modes, is a good idea in general;
the change in AddUsersIfInteresting does this. However,
there were side effects....
It is also possible for recursing outside the loop to
introduce another IV where there was only 1 before (if
the refs inside are not scaled and the ref outside is).
I don't think this is a common case, but it's in the testsuite.
It is right to be very aggressive about getting rid of
such introduced IVs (CheckForIVReuse and the handling of
nonzero RewriteFactor in StrengthReduceStridedIVUsers).
In the testcase in question the new IV produced this way
has both a nonconstant stride and a nonzero base, neither
of which was handled before. (This patch does not handle
all the cases where this can happen.) And when inserting
new code that feeds into a PHI, it's right to put such
code at the original location rather than in the PHI's
immediate predecessor(s) when the original location is outside
the loop (a case that couldn't happen before)
(RewriteInstructionToUseNewBase); better to avoid making
multiple copies of it in this case.
Everything above is exercised in
CodeGen/X86/lsr-negative-stride.ll (and ifcvt4 in ARM which is
the same IR).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61178 91177308-0d34-0410-b5e6-96231b3b80d8
nodes. This allows it to do fairly general phi insertion if a
load from a pointer global wants to be SRAd but the load is used
by (recursive) phi nodes. This fixes a pessimization on ppc
introduced by Load PRE.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61123 91177308-0d34-0410-b5e6-96231b3b80d8
can be negative. Keep track of whether all uses of
an IV are outside the loop. Some cosmetics; no
functional change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61109 91177308-0d34-0410-b5e6-96231b3b80d8
consistently for deleting branches. In addition to being slightly
more readable, this makes SimplifyCFG a bit better
about cleaning up after itself when it makes conditions unused.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61100 91177308-0d34-0410-b5e6-96231b3b80d8
CFG when there is exactly one predecessor where the load is not available.
This is designed to not increase code size but still eliminate partially
redundant loads. This fires 1765 times on 403.gcc even though it doesn't
do critical edge splitting yet (the most common reason for it to fail).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61027 91177308-0d34-0410-b5e6-96231b3b80d8
cleans up the generated code a bit. This should have the added benefit of
not randomly renaming functions/globals like my previous patch did. :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61023 91177308-0d34-0410-b5e6-96231b3b80d8
llvm[2]: Linking Release executable opt (without symbols)
...
Undefined symbols:
"llvm::APFloat::IEEEsingle", referenced from:
__ZN4llvm7APFloat10IEEEsingleE$non_lazy_ptr in libLLVMCore.a(Constants.o)
__ZN4llvm7APFloat10IEEEsingleE$non_lazy_ptr in libLLVMCore.a(AsmWriter.o)
__ZN4llvm7APFloat10IEEEsingleE$non_lazy_ptr in libLLVMCore.a(ConstantFold.o)
"llvm::APFloat::IEEEdouble", referenced from:
__ZN4llvm7APFloat10IEEEdoubleE$non_lazy_ptr in libLLVMCore.a(Constants.o)
__ZN4llvm7APFloat10IEEEdoubleE$non_lazy_ptr in libLLVMCore.a(AsmWriter.o)
__ZN4llvm7APFloat10IEEEdoubleE$non_lazy_ptr in libLLVMCore.a(ConstantFold.o)
ld: symbol(s) not found
This is in release mode. To replicate, compile llvm and llvm-gcc in optimized
mode. Then build llvm, in optimized mode, with the newly created compiler.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60977 91177308-0d34-0410-b5e6-96231b3b80d8
of a pointer. This allows is to catch more equivalencies. For example,
the type_lists_compatible_p function used to require two iterations of
the gvn pass (!) to delete its 18 redundant loads because the first pass
would CSE all the addressing computation cruft, which would unblock the
second memdep/gvn passes from recognizing them. This change allows
memdep/gvn to catch all 18 when run just once on the function (as is
typical :) instead of just 3.
On all of 403.gcc, this bumps up the # reundandancies found from:
63 gvn - Number of instructions PRE'd
153991 gvn - Number of instructions deleted
50069 gvn - Number of loads deleted
to:
63 gvn - Number of instructions PRE'd
154137 gvn - Number of instructions deleted
50185 gvn - Number of loads deleted
+120 loads deleted isn't bad.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60799 91177308-0d34-0410-b5e6-96231b3b80d8
MemDep::getNonLocalPointerDependency method. There are
some open issues with this (missed optimizations) and
plenty of future work, but this does allow GVN to eliminate
*slightly* more loads (49246 vs 49033).
Switching over now allows simplification of the other code
path in memdep.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60780 91177308-0d34-0410-b5e6-96231b3b80d8