The greedy register allocator revealed some problems with the value mapping in
SplitKit. We would sometimes start mapping values before all defs were known,
and that could change a value from a simple 1-1 mapping to a multi-def mapping
that requires ssa update.
The new approach collects all defs and register assignments first without
filling in any live intervals. Only when finish() is called, do we compute
liveness and mapped values. At this time we know with certainty which values map
to multiple values in a split range.
This also has the advantage that we can compute live ranges based on the
remaining uses after rematerializing at split points.
The current implementation has many opportunities for compile time optimization.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124765 91177308-0d34-0410-b5e6-96231b3b80d8
overflow (nsw flag), which was disabled because it breaks 254.gap. I have
informed the GAP authors of the mistake in their code, and arranged for the
testsuite to use -fwrapv when compiling this benchmark.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124746 91177308-0d34-0410-b5e6-96231b3b80d8
This makes the job of the later optzn passes easier, allowing the vast amount of
icmp transforms to chew on it.
We transform 840 switches in gcc.c, leading to a 16k byte shrink of the resulting
binary on i386-linux.
The testcase from README.txt now compiles into
decl %edi
cmpl $3, %edi
sbbl %eax, %eax
andl $1, %eax
ret
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124724 91177308-0d34-0410-b5e6-96231b3b80d8
may be useful to understand "none", this is not the place for it. Tweak
the fix to Normalize while there: the fix added in 123990 works correctly,
but I like this way better. Finally, now that Triple understands some
non-trivial environment values, teach the unittests about them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124720 91177308-0d34-0410-b5e6-96231b3b80d8
that might have changed been affected by a merge elsewhere will have been
removed from the function set, and it isn't needed for performance because we
call grow() ahead of time to prevent reallocations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124717 91177308-0d34-0410-b5e6-96231b3b80d8
reassociation. No testcase, because I wasn't able to create a testcase
which actually demonstrates a problem.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124713 91177308-0d34-0410-b5e6-96231b3b80d8
prefix would be misinterpreted in some cases on 32-bit
x86 platforms. Thanks to Olivier Meurant for identifying
the bug.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124709 91177308-0d34-0410-b5e6-96231b3b80d8
the load, then it may be legal to transform the load and store to integer
load and store of the same width.
This is done if the target specified the transformation as profitable. e.g.
On arm, this can transform:
vldr.32 s0, []
vstr.32 s0, []
to
ldr r12, []
str r12, []
rdar://8944252
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124708 91177308-0d34-0410-b5e6-96231b3b80d8
This is similar to the -unroll-threshold option. There should be no change in
behavior when -tail-dup-size is not explicit on the llc command line.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124564 91177308-0d34-0410-b5e6-96231b3b80d8
to do this and more, but would only do it if X/Y had only one use. Spotted as the
most common missed simplification in SPEC by my auto-simplifier, now that it knows
about nuw/nsw/exact flags. This removes a bunch of multiplications from 447.dealII
and 483.xalancbmk. It also removes a lot from tramp3d-v4, which results in much
more inlining.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124560 91177308-0d34-0410-b5e6-96231b3b80d8
This happens all the time when a smul is promoted to a larger type.
On x86-64 we now compile "int test(int x) { return x/10; }" into
movslq %edi, %rax
imulq $1717986919, %rax, %rax
movq %rax, %rcx
shrq $63, %rcx
sarq $34, %rax <- used to be "shrq $32, %rax; sarl $2, %eax"
addl %ecx, %eax
This fires 96 times in gcc.c on x86-64.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124559 91177308-0d34-0410-b5e6-96231b3b80d8
The DEBUG() call at line 606 demands to see raw_ostream's definition. I have no idea why this seems to only break MSVC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124545 91177308-0d34-0410-b5e6-96231b3b80d8
This happens e.g. for code like "X - X%10" where we lower the modulo operation
to a series of multiplies and shifts that are then subtracted from X, leading to
this missed optimization.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124532 91177308-0d34-0410-b5e6-96231b3b80d8
Jakob Stoklund Olesen
Devang Patel
Duncan Sands
Bob Wilson
Benjamin Kramer
Richard Osborne
Nick Lewycky
Dan Gohman
Sean Callanan
Evan Cheng
Matt Beaumont-Gay
Anton Korobeynikov
Jay Foad
Carl Norum
Rafael Espindola
Eric Christopher
Roman Divacky
David Greene
Chris Lattner
Anders Carlsson
Francois Pichet
Frits van Bommel