t:
mov %EDX, DWORD PTR [%ESP + 4]
mov %ECX, 2
mov %EAX, %EDX
sar %EDX, 31
idiv %ECX
mov %EAX, %EDX
ret
Generate:
t:
mov %ECX, DWORD PTR [%ESP + 4]
*** mov %EAX, %ECX
cdq
and %ECX, 1
xor %ECX, %EDX
sub %ECX, %EDX
*** mov %EAX, %ECX
ret
Note that the two marked moves are redundant, and should be eliminated by the
register allocator, but aren't.
Compare this to GCC, which generates:
t:
mov %eax, DWORD PTR [%esp+4]
mov %edx, %eax
shr %edx, 31
lea %ecx, [%edx+%eax]
and %ecx, -2
sub %eax, %ecx
ret
or ICC 8.0, which generates:
t:
movl 4(%esp), %ecx #3.5
movl $-2147483647, %eax #3.25
imull %ecx #3.25
movl %ecx, %eax #3.25
sarl $31, %eax #3.25
addl %ecx, %edx #3.25
subl %edx, %eax #3.25
addl %eax, %eax #3.25
negl %eax #3.25
subl %eax, %ecx #3.25
movl %ecx, %eax #3.25
ret #3.25
We would be in great shape if not for the moves.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16763 91177308-0d34-0410-b5e6-96231b3b80d8
* Update comments
* Rearrange code a bit
* Finally ELIMINATE the GAS workaround emitter for Intel mode. woot!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16647 91177308-0d34-0410-b5e6-96231b3b80d8
old and broken AT&T syntax assemblers. The problem with this hack is that
*SOME* forms of the fdiv and fsub instructions have the 'r' bit inverted.
This was a real pain to figure out, but is trivially easy to support: thus
we are now bug compatible with gas and gcc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16644 91177308-0d34-0410-b5e6-96231b3b80d8
Intel and AT&T style assembly language. The ultimate goal of this is to
eliminate the GasBugWorkaroundEmitter class, but for now AT&T style emission
is not fully operational.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16639 91177308-0d34-0410-b5e6-96231b3b80d8
hopefully lead to the death of the 'GasBugWorkaroundEmitter'. This also
includes changes to wrap the whole file to 80 columns! Woot! :)
Note that the AT&T style output has not been tested at all.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16638 91177308-0d34-0410-b5e6-96231b3b80d8
won't work if not compiled in V9 mode, currently by GCC only, because Sun's
system compiler does not tell us if it's a V8 or V9 system.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16602 91177308-0d34-0410-b5e6-96231b3b80d8
Copy constant-pool entries' addresses into registers before loading out of them,
to avoid errors from the assembler.
Handle loading call args past the 6th one off the stack.
Add IMPLICIT_DEF pseudo-instrs for double and long arguments passed in register
pairs.
Use FpMOVD to copy doubles around instead of the horrible store-load thing we
were doing before.
Handle 'ret double' and 'ret long'.
Fix a bug in handling 'and/or/xor long'.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16577 91177308-0d34-0410-b5e6-96231b3b80d8
integers that we can use as immediate values in instructions.
Example from yacr2:
- lis r10, -1
- ori r10, r10, 65535
- add r28, r28, r10
+ addi r28, r28, -1
addi r7, r7, 1
addi r9, r9, 1
b .LBB_main_9 ; loopentry.1.i214
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16566 91177308-0d34-0410-b5e6-96231b3b80d8