Commit Graph

18 Commits

Author SHA1 Message Date
3dd08734c1 optimize bitcasts from large integers to vector into vector
element insertion from the pieces that feed into the vector.
This handles a pattern that occurs frequently due to code
generated for the x86-64 abi.  We now compile something like
this:

struct S { float A, B, C, D; };
struct S g;
struct S bar() { 
  struct S A = g;
  ++A.A;
  ++A.C;
  return A;
}

into all nice vector operations:

_bar:                                   ## @bar
## BB#0:                                ## %entry
	movq	_g@GOTPCREL(%rip), %rax
	movss	LCPI1_0(%rip), %xmm1
	movss	(%rax), %xmm0
	addss	%xmm1, %xmm0
	pshufd	$16, %xmm0, %xmm0
	movss	4(%rax), %xmm2
	movss	12(%rax), %xmm3
	pshufd	$16, %xmm2, %xmm2
	unpcklps	%xmm2, %xmm0
	addss	8(%rax), %xmm1
	pshufd	$16, %xmm1, %xmm1
	pshufd	$16, %xmm3, %xmm2
	unpcklps	%xmm2, %xmm1
	ret

instead of icky integer operations:

_bar:                                   ## @bar
	movq	_g@GOTPCREL(%rip), %rax
	movss	LCPI1_0(%rip), %xmm1
	movss	(%rax), %xmm0
	addss	%xmm1, %xmm0
	movd	%xmm0, %ecx
	movl	4(%rax), %edx
	movl	12(%rax), %esi
	shlq	$32, %rdx
	addq	%rcx, %rdx
	movd	%rdx, %xmm0
	addss	8(%rax), %xmm1
	movd	%xmm1, %eax
	shlq	$32, %rsi
	addq	%rax, %rsi
	movd	%rsi, %xmm1
	ret

This resolves rdar://8360454



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112343 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-28 01:20:38 +00:00
4ece577019 Enhance the shift propagator to handle the case when you have:
A = shl x, 42
...
B = lshr ..., 38

which can be transformed into:
A = shl x, 4
...

iff we can prove that the would-be-shifted-in bits
are already zero.  This eliminates two shifts in the testcase
and allows eliminate of the whole i128 chain in the real example.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112314 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-27 22:53:44 +00:00
29cc0b3660 Implement a pretty general logical shift propagation
framework, which is good at ripping through bitfield
operations.  This generalize a bunch of the existing
xforms that instcombine does, such as 
  (x << c) >> c -> and
to handle intermediate logical nodes.  This is useful for
ripping up the "promote to large integer" code produced by
SRoA.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112304 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-27 22:24:38 +00:00
2d0822a937 remove some special shift cases that have been subsumed into the
more general simplify demanded bits logic.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112291 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-27 21:04:34 +00:00
de9f5452d3 use ArgOperand API
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106707 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-24 00:44:01 +00:00
551754c495 Revert 101465, it broke internal OpenGL testing.
Probably the best way to know that all getOperand() calls have been handled
is to replace that API instead of updating.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101579 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-16 23:37:20 +00:00
4ec2258ffb reapply r101434
with a fix for self-hosting

rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101465 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-16 15:33:14 +00:00
607a7ab3da back out r101423 and r101397, they break llvm-gcc self-host on darwin10
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101434 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-16 01:16:20 +00:00
2ff961f668 reapply r101364, which has been backed out in r101368
with a fix

rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101397 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-15 20:51:13 +00:00
9ee1720811 back out r101364, as it trips the linux nightlybot on some clang C++ tests
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101368 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-15 12:46:56 +00:00
165dac08d1 rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101364 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-15 10:49:53 +00:00
f7d0d163c5 fix a potential overflow issue Eli pointed out.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94336 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-23 23:31:46 +00:00
818ff34bc0 implement a simple instcombine xform that has been in the
readme forever.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94318 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-23 18:49:30 +00:00
cd5adbbc0c my instcombine transformations to make extension elimination more
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
2010-01-18 22:19:16 +00:00
f4fb91181c change the preferred canonical form for a sign extension to be
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
2010-01-10 07:08:30 +00:00
abff82d99e fix indentation of switch statements, no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93106 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-10 06:59:55 +00:00
a85732fa3b teach instcombine to delete sign extending shift pairs (sra(shl X, C), C) when
the input is already sign extended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93019 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-08 19:04:21 +00:00
9cdd5f3fe3 split instcombine of shifts out to its own file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92709 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 07:44:46 +00:00