present in the bottom of the CFG triangle, as the transformation isn't
ever valuable if the branch can't be eliminated.
Also, unify some heuristics between SimplifyCFG's multiple
if-converters, for consistency.
This fixes rdar://10627242.
llvm-svn: 147630
code can incorrectly move the load across a store. This never
happens in practice today, but only because the current
heuristics accidentally preclude it.
llvm-svn: 147623
a combined-away node and the result of the combine isn't substantially
smaller than the input, it's just canonicalized. This is the first part
of a significant (7%) performance gain for Snappy's hot decompression
loop.
llvm-svn: 147604
Testing: passed 'make check' including LIT tests for all sequences being handled (both SSE and AVX)
Reviewers: Evan Cheng, David Blaikie, Bruno Lopes, Elena Demikhovsky, Chad Rosier, Anton Korobeynikov
llvm-svn: 147601
This small bit of ASM code is sufficient to do what the old algorithm did:
movq %rax, %xmm0
punpckldq (c0), %xmm0 // c0: (uint4){ 0x43300000U, 0x45300000U, 0U, 0U }
subpd (c1), %xmm0 // c1: (double2){ 0x1.0p52, 0x1.0p52 * 0x1.0p32 }
#ifdef __SSE3__
haddpd %xmm0, %xmm0
#else
pshufd $0x4e, %xmm0, %xmm1
addpd %xmm1, %xmm0
#endif
It's arguably faster. One caveat, the 'haddpd' instruction isn't very fast on
all processors.
<rdar://problem/7719814>
llvm-svn: 147593
Now that canRealignStack() understands frozen reserved registers, it is
safe to use it for aligned spill instructions.
It will only return true if the registers reserved at the beginning of
register allocation allow for dynamic stack realignment.
<rdar://problem/10625436>
llvm-svn: 147579
Once register allocation has started the reserved registers are frozen.
Fix the ARM canRealignStack() hook to respect the frozen register state.
Now the hook returns false if register allocation was started with frame
pointer elimination enabled.
It also returns false if register allocation started without a reserved
base pointer, and stack realignment would require a base pointer. This
bug was breaking oggenc on armv6.
No test case, an upcoming patch will use this functionality to realign
the stack for spill slots when possible.
llvm-svn: 147578
The register allocators don't currently support adding reserved
registers while they are running. Extend the MRI API to keep track of
the set of reserved registers when register allocation started.
Target hooks like hasFP() and needsStackRealignment() can look at this
set to avoid reserving more registers during register allocation.
llvm-svn: 147577
Using DenseMap iterators isn't free as they have to check for empty
buckets. Dominator queries are common so this gives a minor speedup.
llvm-svn: 147544
Get back getHostTriple.
For JIT compilation, use the host triple instead of the default
target: this fixes some JIT testcases that used to fail when the
compiler has been configured as a cross compiler.
llvm-svn: 147542
versions derive from them.
- JALR64 is not needed since N64 does not emit jal.
- Add template parameter to BranchLink that sets the rt field.
- Fix the set of temporary registers for O32 and N64.
llvm-svn: 147518
(x > y) ? x : y
=>
(x >= y) ? x : y
So for something like
(x - y) > 0 : (x - y) ? 0
It will be
(x - y) >= 0 : (x - y) ? 0
This makes is possible to test sign-bit and eliminate a comparison against
zero. e.g.
subl %esi, %edi
testl %edi, %edi
movl $0, %eax
cmovgl %edi, %eax
=>
xorl %eax, %eax
subl %esi, $edi
cmovsl %eax, %edi
rdar://10633221
llvm-svn: 147512
Before we'd get:
$ clang t.c
fatal error: error in backend: Invalid operand for inline asm constraint 'i'!
Now we get:
$ clang t.c
t.c:16:5: error: invalid operand for inline asm constraint 'i'!
"movq (%4), %%mm0\n"
^
Which at least gets us the inline asm that is the problem.
llvm-svn: 147502
This patch caused a miscompilation of oggenc because a frame pointer was
suddenly needed halfway through register allocation.
<rdar://problem/10625436>
llvm-svn: 147487
