the JIT had last night.

llvm-svn: 16766

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.

llvm-svn: 16763

s:   ;; X / 4
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %ECX, %EAX
        sar %ECX, 1
        shr %ECX, 30
        mov %EDX, %EAX
        add %EDX, %ECX
        sar %EAX, 2
        ret

When we really meant:

s:
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %ECX, %EAX
        sar %ECX, 1
        shr %ECX, 30
        add %EAX, %ECX
        sar %EAX, 2
        ret

Hey, this also reduces register pressure too :)

llvm-svn: 16761

instead of:

s:   ;; X / 2
        movl 4(%esp), %eax
        movl %eax, %ecx
        shrl $31, %ecx
        movl %eax, %edx
        addl %ecx, %edx
        sarl $1, %eax
        ret

t:   ;; X / -2
        movl 4(%esp), %eax
        movl %eax, %ecx
        shrl $31, %ecx
        movl %eax, %edx
        addl %ecx, %edx
        sarl $1, %eax
        negl %eax
        ret

Emit:

s:
        movl 4(%esp), %eax
        cmpl $-2147483648, %eax
        sbbl $-1, %eax
        sarl $1, %eax
        ret

t:
        movl 4(%esp), %eax
        cmpl $-2147483648, %eax
        sbbl $-1, %eax
        sarl $1, %eax
        negl %eax
        ret

llvm-svn: 16760

llvm-svn: 16759

* Update comments
* Rearrange code a bit
* Finally ELIMINATE the GAS workaround emitter for Intel mode.  woot!

llvm-svn: 16647

may now choose their output format with the -x86-asm-syntax={intel|att} flag.

llvm-svn: 16646

llvm-svn: 16645

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.

llvm-svn: 16644

llvm-svn: 16642

llvm-svn: 16641

llvm-svn: 16640

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.

llvm-svn: 16639

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.

llvm-svn: 16638

are only used by the stackifier when transforming FPn register
allocations to the real stack file x87 registers.

llvm-svn: 16472

front-end in gcc does not mangle classes in anonymous namespaces correctly.

llvm-svn: 16469

Patch contributed by Paolo Invernizzi. Thanks Paolo!

llvm-svn: 16368

llvm-svn: 16353

specify aliases directly in register definitions.

Patch contributed by Jason Eckhardt!

llvm-svn: 16330

llvm-svn: 16299

FpSETRESULT.

llvm-svn: 16247

value is returned in that register. The pseudo instructions
FpGETRESULT and FpSETRESULT shold also have an implicity use and def
of ST0 repsecitvely.

llvm-svn: 16246

Move include/Config and include/Support into include/llvm/Config,
include/llvm/ADT and include/llvm/Support. From here on out, all LLVM
public header files must be under include/llvm/.

llvm-svn: 16137

improvements on instruction selection that account for register and frame
index bases.

Patch contributed by Jeff Cohen. Thanks Jeff!

llvm-svn: 16110

llvm-svn: 16018

llvm-svn: 16017

llvm-svn: 15974

llvm-svn: 15973

llvm-svn: 15897

Changes to make this more similar to the ppc asmprinter

llvm-svn: 15890

llvm-svn: 15872

drops our half-assed support for cygwin, which noone uses and doesn't work
anyway.

llvm-svn: 15839

llvm-svn: 15787

llvm-svn: 15780

llvm-svn: 15774

Eliminate MachineFunction& argument from eliminateFrameIndex in x86 Target.  Get MachineFunction from MachineInstruction's parent's parent

llvm-svn: 15739

old asmprinter.

llvm-svn: 15660

llvm-svn: 15659

llvm-svn: 15658

llvm-svn: 15657