Commit Graph

16 Commits

Author SHA1 Message Date
Stephen Lin f799e3f944 Convert CodeGen/*/*.ll tests to use the new CHECK-LABEL for easier debugging. No functionality change and all tests pass after conversion.
This was done with the following sed invocation to catch label lines demarking function boundaries:
    sed -i '' "s/^;\( *\)\([A-Z0-9_]*\):\( *\)test\([A-Za-z0-9_-]*\):\( *\)$/;\1\2-LABEL:\3test\4:\5/g" test/CodeGen/*/*.ll
which was written conservatively to avoid false positives rather than false negatives. I scanned through all the changes and everything looks correct.

llvm-svn: 186258
2013-07-13 20:38:47 +00:00
Owen Anderson de89ecf1fc Reapply r174343, with a fix for a scary DAG combine bug where it failed to differentiate between the alignment of the
base point of a load, and the overall alignment of the load.  This caused infinite loops in DAG combine with the
original application of this patch.

ORIGINAL COMMIT LOG:
When the target-independent DAGCombiner inferred a higher alignment for a load,
it would replace the load with one with the higher alignment.  However, it did
not place the new load in the worklist, which prevented later DAG combines in
the same phase (for example, target-specific combines) from ever seeing it.

This patch corrects that oversight, and updates some tests whose output changed
due to slightly different DAGCombine outputs.

llvm-svn: 174431
2013-02-05 19:24:39 +00:00
NAKAMURA Takumi 3753b28cd2 Revert r174343, "When the target-independent DAGCombiner inferred a higher alignment for a load,"
It caused hangups in compiling clang/lib/Parse/ParseDecl.cpp and clang/lib/Driver/Tools.cpp in stage2 on some hosts.

llvm-svn: 174374
2013-02-05 14:44:16 +00:00
Owen Anderson a47fdbb032 When the target-independent DAGCombiner inferred a higher alignment for a load,
it would replace the load with one with the higher alignment.  However, it did
not place the new load in the worklist, which prevented later DAG combines in
the same phase (for example, target-specific combines) from ever seeing it.

This patch corrects that oversight, and updates some tests whose output changed
due to slightly different DAGCombine outputs.

llvm-svn: 174343
2013-02-05 06:25:30 +00:00
Benjamin Kramer 3aab6a86a2 PR13326: Fix a subtle edge case in the udiv -> magic multiply generator.
This caused 6 of 65k possible 8 bit udivs to be wrong.

llvm-svn: 160058
2012-07-11 18:31:59 +00:00
Andrew Trick 8523b16ff5 Instruction scheduling itinerary for Intel Atom.
Adds an instruction itinerary to all x86 instructions, giving each a default latency of 1, using the InstrItinClass IIC_DEFAULT.

Sets specific latencies for Atom for the instructions in files X86InstrCMovSetCC.td, X86InstrArithmetic.td, X86InstrControl.td, and X86InstrShiftRotate.td. The Atom latencies for the remainder of the x86 instructions will be set in subsequent patches.

Adds a test to verify that the scheduler is working.

Also changes the scheduling preference to "Hybrid" for i386 Atom, while leaving x86_64 as ILP.

Patch by Preston Gurd!

llvm-svn: 149558
2012-02-01 23:20:51 +00:00
Jakob Stoklund Olesen 4931bbc671 Be more aggressive about following hints.
RAGreedy::tryAssign will now evict interference from the preferred
register even when another register is free.

To support this, add the EvictionCost struct that counts how many hints
are broken by an eviction. We don't want to break one hint just to
satisfy another.

Rename canEvict to shouldEvict, and add the first bit of eviction policy
that doesn't depend on spill weights: Always make room in the preferred
register as long as the evictees can be split and aren't already
assigned to their preferred register.

Also make the CSR avoidance more accurate. When looking for a cheaper
register it is OK to use a new volatile register. Only CSR aliases that
have never been used before should be avoided.

llvm-svn: 134735
2011-07-08 20:46:18 +00:00
Benjamin Kramer cfcea12fe2 BuildUDIV: If the divisor is even we can simplify the fixup of the multiplied value by introducing an early shift.
This allows us to compile "unsigned foo(unsigned x) { return x/28; }" into
	shrl	$2, %edi
	imulq	$613566757, %rdi, %rax
	shrq	$32, %rax
	ret

instead of
	movl    %edi, %eax
	imulq   $613566757, %rax, %rcx
	shrq    $32, %rcx
	subl    %ecx, %eax
	shrl    %eax
	addl    %ecx, %eax
	shrl    $4, %eax

on x86_64

llvm-svn: 127829
2011-03-17 20:39:14 +00:00
Cameron Zwarich 8731d0cc83 The signed version of our "magic number" computation for the integer approximation
of a constant had a minor typo introduced when copying it from the book, which
caused it to favor negative approximations over positive approximations in many
cases. Positive approximations require fewer operations beyond the multiplication.

In the case of division by 3, we still generate code that is a single instruction
larger than GCC's code.

llvm-svn: 126097
2011-02-21 00:22:02 +00:00
Benjamin Kramer 946e1522b6 Teach DAGCombine to fold fold (sra (trunc (sr x, c1)), c2) -> (trunc (sra x, c1+c2) when c1 equals the amount of bits that are truncated off.
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.

llvm-svn: 124559
2011-01-30 16:38:43 +00:00
Dale Johannesen a94e36bbee Reapply 122353-122355 with fixes. 122354 was wrong;
the shift type was needed one place, the shift count
type another.  The transform in 123555 had the same
problem.

llvm-svn: 122366
2010-12-21 21:55:50 +00:00
Dale Johannesen 87c47499c6 Revert 122353-122355 for the moment, they broke stuff.
llvm-svn: 122360
2010-12-21 21:22:27 +00:00
Dale Johannesen fa5dc82fda Get the type of a shift from the shift, not from its shift
count operand.  These should be the same but apparently are
not always, and this is cleaner anyway.  This improves the
code in an existing test.

llvm-svn: 122354
2010-12-21 20:06:19 +00:00
Chris Lattner 15090e1eb0 take care of some todos, transforming [us]mul_lohi into
a wider mul if the wider mul is legal.

llvm-svn: 121848
2010-12-15 06:04:19 +00:00
Chris Lattner c3301e970c merge two tests
llvm-svn: 121847
2010-12-15 05:58:59 +00:00
Chris Lattner 8e21a02c19 rename test
llvm-svn: 121697
2010-12-13 08:39:40 +00:00