stack slot and store if the SINT_TO_FP is actually legal. This allows
us to compile:
double a(double b) {return (unsigned)b;}
to:
_a:
cvttsd2siq %xmm0, %rax
movl %eax, %eax
cvtsi2sdq %rax, %xmm0
ret
instead of:
_a:
subq $8, %rsp
cvttsd2siq %xmm0, %rax
movl %eax, %eax
cvtsi2sdq %rax, %xmm0
addq $8, %rsp
ret
crazy.
llvm-svn: 47660
_test:
movl %edi, %eax
ret
instead of:
_test:
movl $4294967295, %ecx
movq %rdi, %rax
andq %rcx, %rax
ret
It would be great to write this as a Pat pattern that used subregs
instead of a 'pseudo' instruction, but I don't know how to do that
in td files.
llvm-svn: 47658
after legalize. Just because a constant is legal (e.g. 0.0 in SSE)
doesn't mean that its negated value is legal (-0.0). We could make
this stronger by checking to see if the negated constant is actually
legal post negation, but it doesn't seem like a big deal.
llvm-svn: 47591
for CellSPU modifications:
- SPUInstrInfo.td refactoring: "multiclass" really is _your_ friend.
- Other improvements based on refactoring effort in SPUISelLowering.cpp,
esp. in SPUISelLowering::PerformDAGCombine(), where zero amount shifts and
rotates are now eliminiated, other scalar-to-vector-to-scalar silliness
is also eliminated.
- 64-bit operations are being implemented, _muldi3.c gcc runtime now
compiles and generates the right code. More work still needs to be done.
llvm-svn: 47532
instead of with mmx registers. This horribleness is apparently
done by gcc to avoid having to insert emms in places that really
should have it. This is the second half of rdar://5741668.
llvm-svn: 47474
GCC apparently does this, and code depends on not having to do
emms when this happens. This is x86-64 only so far, second half
should handle x86-32.
rdar://5741668
llvm-svn: 47470
inline asms.
Fix PR2078 by marking aliases of registers used when a register is
marked used. This prevents EAX from being allocated when AX is listed
in the clobber set for the asm.
llvm-svn: 47426
has plain one-result scalar integer multiplication instructions.
This avoids expanding such instructions into MUL_LOHI sequences that
must be special-cased at isel time, and avoids the problem with that
code that provented memory operands from being folded.
This fixes PR1874, addressesing the most common case. The uncommon
cases of optimizing multiply-high operations will require work
in DAGCombiner.
llvm-svn: 47277
