when it should have been and'd with LowBits. Fix that and while there beef
up the logic in the case of a negative LHS.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94745 91177308-0d34-0410-b5e6-96231b3b80d8
This was already being done in SSAUpdater::GetValueAtEndOfBlock so I've
just changed SSAUpdater to check for existing PHIs in both places.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94690 91177308-0d34-0410-b5e6-96231b3b80d8
"sext cond" instead of a select. This simplifies some instcombine
code, matches the policy for zext (cond ? 1 : 0 -> zext), and allows
us to generate better code for a testcase on ppc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94339 91177308-0d34-0410-b5e6-96231b3b80d8
for arbitrary terminators in predecessors, don't assume
it is a conditional or uncond branch. The testcase shows
an example where they can happen with switches.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94323 91177308-0d34-0410-b5e6-96231b3b80d8
externally visible function, it can still find all callers of it and replace
the parameters to a dead argument with undef.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94322 91177308-0d34-0410-b5e6-96231b3b80d8
handle the case when we can infer an input to the xor
from all inputs that agree, instead of going into an
infinite loop. Another part of PR6199
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94321 91177308-0d34-0410-b5e6-96231b3b80d8
if one of the vectors didn't have elements (such as undef). Fixes PR 6096.
Fix an issue in the constant folder where fcmp (<2 x %ty>, <2 x %ty>) would
have <2 x i1> type if constant folding was successful and i1 type if it wasn't.
This exposed a related issue in the bitcode reader.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94069 91177308-0d34-0410-b5e6-96231b3b80d8
This new version is much more aggressive about doing "full" reduction in
cases where it reduces register pressure, and also more aggressive about
rewriting induction variables to count down (or up) to zero when doing so
reduces register pressure.
It currently uses fairly simplistic algorithms for finding reuse
opportunities, but it introduces a new framework allows it to combine
multiple strategies at once to form hybrid solutions, instead of doing
all full-reduction or all base+index.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94061 91177308-0d34-0410-b5e6-96231b3b80d8
are the same. I had already fixed a similar problem where the source and
destination were different bitcasts derived from the same alloca, but the
previous fix still did not handle the case where both operands are exactly
the same value. Radar 7552893.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93848 91177308-0d34-0410-b5e6-96231b3b80d8
aggressive changed the canonical form from sext(trunc(x)) to ashr(lshr(x)),
make sure to transform a couple more things into that canonical form,
and catch a case where we missed turning zext/shl/ashr into a single sext.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93787 91177308-0d34-0410-b5e6-96231b3b80d8
added to the FSub version. However, the original version of this xform guarded
against doing this for floating point (!Op0->getType()->isFPOrFPVector()).
This is causing LLVM to perform incorrect xforms for code like:
void func(double *rhi, double *rlo, double xh, double xl, double yh, double yl){
double mh, ml;
double c = 134217729.0;
double up, u1, u2, vp, v1, v2;
up = xh*c;
u1 = (xh - up) + up;
u2 = xh - u1;
vp = yh*c;
v1 = (yh - vp) + vp;
v2 = yh - v1;
mh = xh*yh;
ml = (((u1*v1 - mh) + (u1*v2)) + (u2*v1)) + (u2*v2);
ml += xh*yl + xl*yh;
*rhi = mh + ml;
*rlo = (mh - (*rhi)) + ml;
}
The last line was optimized away, but rl is intended to be the difference
between the infinitely precise result of mh + ml and after it has been rounded
to double precision.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93369 91177308-0d34-0410-b5e6-96231b3b80d8
in JT.
2) When cloning blocks for PHI or xor conditions, use
instsimplify to simplify the code as we go. This allows us to
squish common cases early in JT which opens up opportunities for
subsequent iterations, and allows it to completely simplify the
testcase.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93253 91177308-0d34-0410-b5e6-96231b3b80d8
condition is a xor with a phi node. This eliminates nonsense
like this from 176.gcc in several places:
LBB166_84:
testl %eax, %eax
- setne %al
- xorb %cl, %al
- notb %al
- testb $1, %al
- je LBB166_85
+ je LBB166_69
+ jmp LBB166_85
This is rdar://7391699
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BitsToClear case. This allows it to promote expressions which have an
and/or/xor after the lshr, promoting cases like test2 (from PR4216)
and test3 (random extample extracted from a spec benchmark).
clang now compiles the code in PR4216 into:
_test_bitfield: ## @test_bitfield
movl %edi, %eax
orl $194, %eax
movl $4294902010, %ecx
andq %rax, %rcx
orl $32768, %edi
andq $39936, %rdi
movq %rdi, %rax
orq %rcx, %rax
ret
instead of:
_test_bitfield: ## @test_bitfield
movl %edi, %eax
orl $194, %eax
movl $4294902010, %ecx
andq %rax, %rcx
shrl $8, %edi
orl $128, %edi
shlq $8, %rdi
andq $39936, %rdi
movq %rdi, %rax
orq %rcx, %rax
ret
which is still not great, but is progress.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93145 91177308-0d34-0410-b5e6-96231b3b80d8
new BitsToClear result which allows us to start promoting
expressions that end with a lshr-by-constant. This is
conservatively correct and better than what we had before
(see testcases) but still needs to be extended further.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93144 91177308-0d34-0410-b5e6-96231b3b80d8
the zext dest type. This allows us to handle test52/53 in cast.ll,
and allows llvm-gcc to generate much better code for PR4216 in -m64
mode:
_test_bitfield: ## @test_bitfield
orl $32962, %edi
movl %edi, %eax
andl $-25350, %eax
ret
This also fixes a bug handling vector extends, ensuring that the
mask produced is a vector constant, not an integer constant.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93127 91177308-0d34-0410-b5e6-96231b3b80d8
elimination of a sign extend to be a win, which simplifies
the client of CanEvaluateSExtd, and allows us to eliminate
more casts (examples taken from real code).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93109 91177308-0d34-0410-b5e6-96231b3b80d8
lshr+ashr instead of trunc+sext. We want to avoid type
conversions whenever possible, it is easier to codegen expressions
without truncates and extensions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93107 91177308-0d34-0410-b5e6-96231b3b80d8
1) don't try to optimize a sext or zext that is only used by a trunc, let
the trunc get optimized first. This avoids some pointless effort in
some common cases since instcombine scans down a block in the first pass.
2) Change the cost model for zext elimination to consider an 'and' cheaper
than a zext. This allows us to do it more aggressively, and for the next
patch to simplify the code quite a bit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93097 91177308-0d34-0410-b5e6-96231b3b80d8
result int by 8 for the first byte. While normally harmless,
if the result is smaller than a byte, this shift is invalid.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93018 91177308-0d34-0410-b5e6-96231b3b80d8
that feeds into a zext, similar to the patch I did yesterday for sext.
There is a lot of room for extension beyond this patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92962 91177308-0d34-0410-b5e6-96231b3b80d8
