Commit Graph

731 Commits

Author SHA1 Message Date
Chris Lattner
dc8e8484e5 Second half of my fixed-sized-alloca patch. This folds the LEA to compute
the alloca address into common operations like loads/stores.

In a simple testcase like this (which is just designed to excersize the
alloca A, nothing more):

int %test(int %X, bool %C) {
        %A = alloca int
        store int %X, int* %A
        store int* %A, int** %G
        br bool %C, label %T, label %F
T:
        call int %test(int 1, bool false)
        %V = load int* %A
        ret int %V
F:
        call int %test(int 123, bool true)
        %V2 = load int* %A
        ret int %V2
}

We now generate:

test:
        sub %ESP, 12
        mov %EAX, DWORD PTR [%ESP + 16]
        mov %CL, BYTE PTR [%ESP + 20]
***     mov DWORD PTR [%ESP + 8], %EAX
        mov %EAX, OFFSET G
        lea %EDX, DWORD PTR [%ESP + 8]
        mov DWORD PTR [%EAX], %EDX
        test %CL, %CL
        je .LBB2 # PC rel: F
.LBB1:  # T
        mov DWORD PTR [%ESP], 1
        mov DWORD PTR [%ESP + 4], 0
        call test
***     mov %EAX, DWORD PTR [%ESP + 8]
        add %ESP, 12
        ret
.LBB2:  # F
        mov DWORD PTR [%ESP], 123
        mov DWORD PTR [%ESP + 4], 1
        call test
***     mov %EAX, DWORD PTR [%ESP + 8]
        add %ESP, 12
        ret

Instead of:

test:
        sub %ESP, 20
        mov %EAX, DWORD PTR [%ESP + 24]
        mov %CL, BYTE PTR [%ESP + 28]
***     lea %EDX, DWORD PTR [%ESP + 16]
***     mov DWORD PTR [%EDX], %EAX
        mov %EAX, OFFSET G
        mov DWORD PTR [%EAX], %EDX
        test %CL, %CL
***     mov DWORD PTR [%ESP + 12], %EDX
        je .LBB2 # PC rel: F
.LBB1:  # T
        mov DWORD PTR [%ESP], 1
        mov %EAX, 0
        mov DWORD PTR [%ESP + 4], %EAX
        call test
***     mov %EAX, DWORD PTR [%ESP + 12]
***     mov %EAX, DWORD PTR [%EAX]
        add %ESP, 20
        ret
.LBB2:  # F
        mov DWORD PTR [%ESP], 123
        mov %EAX, 1
        mov DWORD PTR [%ESP + 4], %EAX
        call test
***     mov %EAX, DWORD PTR [%ESP + 12]
***     mov %EAX, DWORD PTR [%EAX]
        add %ESP, 20
        ret

llvm-svn: 13557
2004-05-13 15:12:43 +00:00
Chris Lattner
94de563118 Substantially improve code generation for address exposed locals (aka fixed
sized allocas in the entry block).  Instead of generating code like this:

entry:
  reg1024 = ESP+1234
... (much later)
  *reg1024 = 17


Generate code that looks like this:
entry:
  (no code generated)
... (much later)
  t = ESP+1234
  *t = 17

The advantage being that we DRAMATICALLY reduce the register pressure for these
silly temporaries (they were all being spilled to the stack, resulting in very
silly code).  This is actually a manual implementation of rematerialization :)

I have a patch to fold the alloca address computation into loads & stores, which
will make this much better still, but just getting this right took way too much time
and I'm sleepy.

llvm-svn: 13554
2004-05-13 07:40:27 +00:00
Chris Lattner
a19bb14155 Pass boolean constants into function calls more efficiently, generating:
mov DWORD PTR [%ESP + 4], 1

instead of:

        mov %EAX, 1
        mov DWORD PTR [%ESP + 4], %EAX

llvm-svn: 13494
2004-05-12 16:35:04 +00:00
Chris Lattner
a407338e12 Fix a fairly serious pessimizaion that was preventing us from efficiently
compiling things like 'add long %X, 1'.  The problem is that we were switching
the order of the operands for longs even though we can't fold them yet.

llvm-svn: 13451
2004-05-10 15:15:55 +00:00
Chris Lattner
0962db8f10 Fix some comments, avoid sign extending booleans when zero extend works fine
llvm-svn: 13440
2004-05-09 23:16:33 +00:00
Chris Lattner
d18c637a37 Generate more efficient code for casting booleans to integers (no sign extension required)
llvm-svn: 13439
2004-05-09 22:28:45 +00:00
Chris Lattner
67c21e74ec Codegen floating point stores of constants into integer instructions. This
allows us to compile:

store float 10.0, float* %P

into:
        mov DWORD PTR [%EAX], 1092616192

instead of:

.CPItest_0:                                     # float 0x4024000000000000
.long   1092616192      # float 10
...
        fld DWORD PTR [.CPItest_0]
        fstp DWORD PTR [%EAX]

llvm-svn: 13409
2004-05-07 21:18:15 +00:00
Chris Lattner
2021030378 Make comparisons against the null pointer as efficient as integer comparisons
against zero.  In particular, don't emit:

        mov %ESI, 0
        cmp %ECX, %ESI

instead, emit:

       test %ECX, %ECX

llvm-svn: 13407
2004-05-07 19:55:55 +00:00
Chris Lattner
42e602b94f Remove unneeded check
llvm-svn: 13355
2004-05-04 19:35:11 +00:00
Chris Lattner
dac54ebbee Improve signed division by power of 2 *dramatically* from this:
div:
        mov %EDX, DWORD PTR [%ESP + 4]
        mov %ECX, 64
        mov %EAX, %EDX
        sar %EDX, 31
        idiv %ECX
        ret

to this:

div:
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %ECX, %EAX
        sar %ECX, 5
        shr %ECX, 26
        mov %EDX, %EAX
        add %EDX, %ECX
        sar %EAX, 6
        ret

Note that the intel compiler is currently making this:

div:
        movl      4(%esp), %edx                                 #3.5
        movl      %edx, %eax                                    #4.14
        sarl      $5, %eax                                      #4.14
        shrl      $26, %eax                                     #4.14
        addl      %edx, %eax                                    #4.14
        sarl      $6, %eax                                      #4.14
        ret                                                     #4.14

Which has one less register->register copy.  (hint hint alkis :)

llvm-svn: 13354
2004-05-04 19:33:58 +00:00
Chris Lattner
cb9a614ea4 Improve code generated for integer multiplications by 2,3,5,9
llvm-svn: 13342
2004-05-04 15:47:14 +00:00
Chris Lattner
4b5d4eb5b1 Remove unused #include
llvm-svn: 13304
2004-05-01 21:29:16 +00:00
Chris Lattner
ffbf667718 Iterate over the Machine CFG that Brian added instead of the LLVM CFG.
Look at all of the pretty minuses. :)

llvm-svn: 13303
2004-05-01 21:27:53 +00:00
Brian Gaeke
bfb4fe5109 Make RequiresFPRegKill() take a MachineBasicBlock arg.
In InsertFPRegKills(), just check the MachineBasicBlock for successors
instead of its corresponding BasicBlock.

llvm-svn: 13213
2004-04-28 04:45:55 +00:00
Brian Gaeke
74ed24c9de In InsertFPRegKills(), use the machine-CFG itself rather than the
LLVM CFG when trying to find the successors of BB.

llvm-svn: 13212
2004-04-28 04:34:16 +00:00
Brian Gaeke
6c03805717 Update the machine-CFG edges whenever we see a branch.
llvm-svn: 13211
2004-04-28 04:19:37 +00:00
Brian Gaeke
0db103b4b3 Use emitWordAt() to emit forward-branch fixups.
llvm-svn: 13120
2004-04-23 17:11:16 +00:00
John Criswell
8a4525ae64 Remove code to adjust the iterator for llvm.readio and llvm.writeio.
The iterator is pointing at the next instruction which should not disappear
when doing the load/store replacement.

llvm-svn: 12954
2004-04-14 21:27:56 +00:00
Chris Lattner
64431dbce7 This is the real fix for Codegen/X86/2004-04-13-FPCMOV-Crash.llx which works
even when the "optimization" I added before is turned off.  It generates this
extremely pointless code:

test:
        fld QWORD PTR [%ESP + 4]
        mov %AL, 0
        test %AL, %AL
        fcmove %ST(0), %ST(0)
        ret

Good thing the optimizer will have removed this before code generation
anyway.  :)

llvm-svn: 12939
2004-04-14 02:42:32 +00:00
John Criswell
94de925685 Added support for the llvm.readio and llvm.writeio intrinsics.
On x86, memory operations occur in-order, so these are just lowered into
volatile loads and stores.

llvm-svn: 12936
2004-04-13 22:13:14 +00:00
Chris Lattner
2ba048528f Implement a small optimization, which papers over the problem in
X86/2004-04-13-FPCMOV-Crash.llx

A more robust fix is to follow.

llvm-svn: 12935
2004-04-13 21:56:09 +00:00
Chris Lattner
8b6bc380e3 Emit the immediate form of in/out when possible.
Fix several bugs in the intrinsics:
  1. Make sure to copy the input registers before the instructions that use them
  2. Make sure to copy the value returned by 'in' out of EAX into the register
     it is supposed to be in.

This fixes assertions when using in/out and linear scan.

llvm-svn: 12896
2004-04-13 17:20:37 +00:00
Chris Lattner
15ac62827e Add immediate forms of in/out. Use let to shorten lines
llvm-svn: 12895
2004-04-13 17:19:31 +00:00
Chris Lattner
ecbade26d5 Add support for new instruction type
llvm-svn: 12894
2004-04-13 17:18:51 +00:00
Chris Lattner
e8e60bf45f Add support for the printImplicitDefsBefore flag
llvm-svn: 12893
2004-04-13 17:18:39 +00:00
Chris Lattner
43f754339a Fix issues that the local allocator has dealing with instructions that implicitly use ST(0)
llvm-svn: 12855
2004-04-12 03:02:48 +00:00
Chris Lattner
9cdc472518 No really, fix printing for LLC. I gotta get a way for CVS to whine at me if
I have unsaved emacs buffers, geeze...

llvm-svn: 12854
2004-04-12 01:52:04 +00:00
Chris Lattner
f1d59be0e8 Correct printing for LLC and the encoding for the JIT
llvm-svn: 12853
2004-04-12 01:50:04 +00:00
Chris Lattner
682a6361c7 Use the fucomi[p] instructions to perform floating point comparisons instead
of the fucom[p][p] instructions.  This allows us to code generate this function

bool %test(double %X, double %Y) {
        %C = setlt double %Y, %X
        ret bool %C
}

... into:

test:
        fld QWORD PTR [%ESP + 4]
        fld QWORD PTR [%ESP + 12]
        fucomip %ST(1)
        fstp %ST(0)
        setb %AL
        movsx %EAX, %AL
        ret

where before we generated:

test:
        fld QWORD PTR [%ESP + 4]
        fld QWORD PTR [%ESP + 12]
        fucompp
**      fnstsw
**      sahf
        setb %AL
        movsx %EAX, %AL
        ret

The two marked instructions (which are the ones eliminated) are very bad,
because they serialize execution of the processor.  These instructions are
available on the PPRO and later, but since we already use cmov's we aren't
losing any portability.

I retained the old code for the day when we decide we want to support back
to the 386.

llvm-svn: 12852
2004-04-12 01:43:36 +00:00
Chris Lattner
c85d92e0b7 Add support for the FUCOMIr instruction
llvm-svn: 12851
2004-04-12 01:39:15 +00:00
Chris Lattner
cfb7144bf1 Add two new instructions
llvm-svn: 12850
2004-04-12 01:38:55 +00:00
Chris Lattner
de47ad3d6f Fix a bug in my load/cast folding patch.
llvm-svn: 12849
2004-04-12 00:23:04 +00:00
Chris Lattner
b3a10e244a Adjust some comments, fix a bug in my previous patch
llvm-svn: 12848
2004-04-12 00:12:04 +00:00
Chris Lattner
24f8b11206 On X86, casting an integer to floating point requires going through memory.
If the source of the cast is a load, we can just use the source memory location,
without having to create a temporary stack slot entry.

Before we code generated this:

double %int(int* %P) {
        %V = load int* %P
        %V2 = cast int %V to double
        ret double %V2
}

into:

int:
        sub %ESP, 4
        mov %EAX, DWORD PTR [%ESP + 8]
        mov %EAX, DWORD PTR [%EAX]
        mov DWORD PTR [%ESP], %EAX
        fild DWORD PTR [%ESP]
        add %ESP, 4
        ret

Now we produce this:

int:
        mov %EAX, DWORD PTR [%ESP + 4]
        fild DWORD PTR [%EAX]
        ret

... which is nicer.

llvm-svn: 12846
2004-04-11 23:21:26 +00:00
Chris Lattner
95cf3f8765 Implement folding of loads into floating point operations. This implements:
test/Regression/CodeGen/X86/fp_load_fold.llx

llvm-svn: 12844
2004-04-11 22:05:45 +00:00
Chris Lattner
b611f10e74 Unify all of the code for floating point +,-,*,/ into one function
llvm-svn: 12842
2004-04-11 21:23:56 +00:00
Chris Lattner
3378d71a55 This implements folding of constant operands into floating point operations
for mul and div.

Instead of generating this:

test_divr:
        fld QWORD PTR [%ESP + 4]
        fld QWORD PTR [.CPItest_divr_0]
        fdivrp %ST(1)
        ret

We now generate this:

test_divr:
        fld QWORD PTR [%ESP + 4]
        fdivr QWORD PTR [.CPItest_divr_0]
        ret

This code desperately needs refactoring, which will come in the next
patch.

llvm-svn: 12841
2004-04-11 21:09:14 +00:00
Chris Lattner
833d84f48a Restructure the mul/div/rem handling code to follow the pattern the other
instructions use.  This doesn't change any functionality except that long
constant expressions of these operations will now magically start working.

llvm-svn: 12840
2004-04-11 20:56:28 +00:00
Chris Lattner
69304a897c Codegen FP adds and subtracts with a constant more efficiently, generating:
fld QWORD PTR [%ESP + 4]
        fadd QWORD PTR [.CPItest_add_0]

instead of:

        fld QWORD PTR [%ESP + 4]
        fld QWORD PTR [.CPItest_add_0]
        faddp %ST(1)

I also intend to do this for mul & div, but it appears that I have to
refactor a bit of code before I can do so.

This is tested by: test/Regression/CodeGen/X86/fp_constant_op.llx

llvm-svn: 12839
2004-04-11 20:26:20 +00:00
Chris Lattner
dda382531e Add some new instructions
llvm-svn: 12838
2004-04-11 20:24:15 +00:00
Chris Lattner
a0681183b6 Relax assertion to make this function work with a broader class of instructions
llvm-svn: 12836
2004-04-11 20:21:06 +00:00
Chris Lattner
d22a1894a0 Two changes:
1. If an incoming argument is dead, don't load it from the stack
  2. Do not code gen noop copies at all (ie, cast int -> uint), not even to
     a move.  This should reduce register pressure for allocators that are
     unable to coallesce away these copies in some cases.

llvm-svn: 12835
2004-04-11 19:21:59 +00:00
Chris Lattner
8b1122d4dc Silence a spurious warning
llvm-svn: 12815
2004-04-10 18:32:01 +00:00
John Criswell
c9c191c41b Reversed the order of the llvm.writeport() operands so that the value
is listed first and the address is listed second.

llvm-svn: 12795
2004-04-09 19:09:14 +00:00
John Criswell
a52a2291d8 Changed assertions to error messages.
llvm-svn: 12787
2004-04-09 15:10:15 +00:00
John Criswell
8740c3767d Changes recommended by Chris:
InstSelectSimple.cpp:
  Change the checks for proper I/O port address size into an exit() instead
  of an assertion.  Assertions aren't used in Release builds, and handling
  this error should be graceful (not that this counts as graceful, but it's
  more graceful).

  Modified the generation of the IN/OUT instructions to have 0 arguments.
X86InstrInfo.td:
  Added the OpSize attribute to the 16 bit IN and OUT instructions.

llvm-svn: 12786
2004-04-08 22:39:13 +00:00
John Criswell
f6b16ea70b Added the llvm.readport and llvm.writeport intrinsics for x86. These do
I/O port instructions on x86.  The specific code sequence is tailored to
the parameters and return value of the intrinsic call.
Added the ability for implicit defintions to be printed in the Instruction
Printer.
Added the ability for RawFrm instruction to print implict uses and
defintions with correct comma output.  This required adjustment to some
methods so that a leading comma would or would not be printed.

llvm-svn: 12782
2004-04-08 20:31:47 +00:00
Jakub Staszak
fc0d9bb7e9 file based off InstSelectSimple.cpp, slowly being replaced by generated code from the really simple X86 instruction selector tablegen backend
llvm-svn: 12715
2004-04-06 19:35:17 +00:00
Jakub Staszak
06dc0add14 Tablgen files for really simple instruction selector
llvm-svn: 12714
2004-04-06 19:34:00 +00:00
Chris Lattner
3808778190 Fix PR313: [x86] JIT miscompiles unsigned short to floating point
llvm-svn: 12711
2004-04-06 19:29:36 +00:00
Chris Lattner
993d6106c7 Fix incorrect encoding of some ADC and SBB instuctions
llvm-svn: 12710
2004-04-06 19:20:32 +00:00
Chris Lattner
54e93df11a Fix a minor bug in previous checking
Enable folding of long seteq/setne comparisons into branches and select instructions
Implement unfolded long relational comparisons against a constants a bit more efficiently

Folding comparisons changes code that looks like this:
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %EDX, DWORD PTR [%ESP + 8]
        mov %ECX, %EAX
        or %ECX, %EDX
        sete %CL
        test %CL, %CL
        je .LBB2 # PC rel: F

into code that looks like this:
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %EDX, DWORD PTR [%ESP + 8]
        mov %ECX, %EAX
        or %ECX, %EDX
        jne .LBB2 # PC rel: F

This speeds up 186.crafty by 6% with llc-ls.

llvm-svn: 12702
2004-04-06 17:34:50 +00:00
Chris Lattner
2d9b28ac0b Improve codegen of long == and != comparisons against constants. Before,
comparing a long against zero got us this:

        sub %ESP, 8
        mov DWORD PTR [%ESP + 4], %ESI
        mov DWORD PTR [%ESP], %EDI
        mov %EAX, DWORD PTR [%ESP + 12]
        mov %EDX, DWORD PTR [%ESP + 16]
        mov %ECX, 0
        mov %ESI, 0
        mov %EDI, %EAX
        xor %EDI, %ECX
        mov %ECX, %EDX
        xor %ECX, %ESI
        or %EDI, %ECX
        sete %CL
        test %CL, %CL
        je .LBB2 # PC rel: F

Now it gets us this:

        mov %EAX, DWORD PTR [%ESP + 4]
        mov %EDX, DWORD PTR [%ESP + 8]
        mov %ECX, %EAX
        or %ECX, %EDX
        sete %CL
        test %CL, %CL
        je .LBB2 # PC rel: F

llvm-svn: 12696
2004-04-06 16:02:27 +00:00
Chris Lattner
fd7b570dff Handle various other important cases of multiplying a long constant immediate. For
example, multiplying X*(1 + (1LL << 32)) now produces:

test:
        mov %ECX, DWORD PTR [%ESP + 4]
        mov %EDX, DWORD PTR [%ESP + 8]
        mov %EAX, %ECX
        add %EDX, %ECX
        ret

[[[Note to Alkis: why isn't linear scan generating this code??  This might be a
 problem with your intervals being too conservative:

test:
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %EDX, DWORD PTR [%ESP + 8]
        add %EDX, %EAX
        ret

end note]]]

Whereas GCC produces this:

T:
        sub     %esp, 12
        mov     %edx, DWORD PTR [%esp+16]
        mov     DWORD PTR [%esp+8], %edi
        mov     %ecx, DWORD PTR [%esp+20]
        xor     %edi, %edi
        mov     DWORD PTR [%esp], %ebx
        mov     %ebx, %edi
        mov     %eax, %edx
        mov     DWORD PTR [%esp+4], %esi
        add     %ebx, %edx
        mov     %edi, DWORD PTR [%esp+8]
        lea     %edx, [%ecx+%ebx]
        mov     %esi, DWORD PTR [%esp+4]
        mov     %ebx, DWORD PTR [%esp]
        add     %esp, 12
        ret

I'm not sure example what GCC is smoking here, but it looks like it has just
confused itself with a bunch of stack slots or something.  The intel compiler
is better, but still not good:

T:
        movl      4(%esp), %edx                                 #2.11
        movl      8(%esp), %eax                                 #2.11
        lea       (%eax,%edx), %ecx                             #3.12
        movl      $1, %eax                                      #3.12
        mull      %edx                                          #3.12
        addl      %ecx, %edx                                    #3.12
        ret                                                     #3.12

llvm-svn: 12693
2004-04-06 04:55:43 +00:00
Chris Lattner
6038e5a4a1 Efficiently handle a long multiplication by a constant. For this testcase:
long %test(long %X) {
        %Y = mul long %X, 123
        ret long %Y
}

we used to generate:

test:
        sub %ESP, 12
        mov DWORD PTR [%ESP + 8], %ESI
        mov DWORD PTR [%ESP + 4], %EDI
        mov DWORD PTR [%ESP], %EBX
        mov %ECX, DWORD PTR [%ESP + 16]
        mov %ESI, DWORD PTR [%ESP + 20]
        mov %EDI, 123
        mov %EBX, 0
        mov %EAX, %ECX
        mul %EDI
        imul %ESI, %EDI
        add %ESI, %EDX
        imul %ECX, %EBX
        add %ESI, %ECX
        mov %EDX, %ESI
        mov %EBX, DWORD PTR [%ESP]
        mov %EDI, DWORD PTR [%ESP + 4]
        mov %ESI, DWORD PTR [%ESP + 8]
        add %ESP, 12
        ret

Now we emit:
test:
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %ECX, DWORD PTR [%ESP + 8]
        mov %EDX, 123
        mul %EDX
        imul %ECX, %ECX, 123
        add %ECX, %EDX
        mov %EDX, %ECX
        ret

Which, incidently, is substantially nicer than what GCC manages:
T:
        sub     %esp, 8
        mov     %eax, 123
        mov     DWORD PTR [%esp], %ebx
        mov     %ebx, DWORD PTR [%esp+16]
        mov     DWORD PTR [%esp+4], %esi
        mov     %esi, DWORD PTR [%esp+12]
        imul    %ecx, %ebx, 123
        mov     %ebx, DWORD PTR [%esp]
        mul     %esi
        mov     %esi, DWORD PTR [%esp+4]
        add     %esp, 8
        lea     %edx, [%ecx+%edx]
        ret

llvm-svn: 12692
2004-04-06 04:29:36 +00:00
Chris Lattner
dd0d31ca2a Improve code generation of long shifts by 32.
On this testcase:

long %test(long %X) {
        %Y = shr long %X, ubyte 32
        ret long %Y
}

instead of:
t:
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %EAX, DWORD PTR [%ESP + 8]
        sar %EAX, 0
        mov %EDX, 0
        ret


we now emit:
test:
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %EAX, DWORD PTR [%ESP + 8]
        mov %EDX, 0
        ret

llvm-svn: 12688
2004-04-06 03:42:38 +00:00
Chris Lattner
7eb61104dc Bugfixes: inc/dec don't set the carry flag!
llvm-svn: 12687
2004-04-06 03:36:57 +00:00
Chris Lattner
8cdbb1fe84 Improve code for passing constant longs as arguments to function calls.
For example, on this instruction:

        call void %test(long 1234)

Instead of this:
        mov %EAX, 1234
        mov %ECX, 0
        mov DWORD PTR [%ESP], %EAX
        mov DWORD PTR [%ESP + 4], %ECX
        call test

We now emit this:
        mov DWORD PTR [%ESP], 1234
        mov DWORD PTR [%ESP + 4], 0
        call test

llvm-svn: 12686
2004-04-06 03:23:00 +00:00
Chris Lattner
2738d6d4a4 Emit more efficient 64-bit operations when the RHS is a constant, and one
of the words of the constant is zeros.  For example:
  Y = and long X, 1234

now generates:
  Yl = and Xl, 1234
  Yh = 0

instead of:
  Yl = and Xl, 1234
  Yh = and Xh, 0

llvm-svn: 12685
2004-04-06 03:15:53 +00:00
Chris Lattner
bdbedf9523 Fix typeo
llvm-svn: 12684
2004-04-06 02:13:25 +00:00
Chris Lattner
606639ed1a Add support for simple immediate handling to long instruction selection.
This allows us to handle code like 'add long %X, 123456789012' more efficiently.

llvm-svn: 12683
2004-04-06 02:11:49 +00:00
Chris Lattner
e84f12a165 The sbb instructions really ARE sbb's, not adc's
llvm-svn: 12682
2004-04-06 02:02:11 +00:00
Chris Lattner
0808f5daa5 Implement negation of longs efficiently. For this testcase:
long %test(long %X) {
        %Y = sub long 0, %X
        ret long %Y
}

We used to generate:

test:
        sub %ESP, 4
        mov DWORD PTR [%ESP], %ESI
        mov %ECX, DWORD PTR [%ESP + 8]
        mov %ESI, DWORD PTR [%ESP + 12]
        mov %EAX, 0
        mov %EDX, 0
        sub %EAX, %ECX
        sbb %EDX, %ESI
        mov %ESI, DWORD PTR [%ESP]
        add %ESP, 4
        ret

Now we generate:

test:
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %EDX, DWORD PTR [%ESP + 8]
        neg %EAX
        adc %EDX, 0
        neg %EDX
        ret

llvm-svn: 12681
2004-04-06 01:48:06 +00:00
Chris Lattner
56dcdcf638 Minor tweak to avoid an extra reg-reg copy that the register allocator has to eliminate
llvm-svn: 12680
2004-04-06 01:25:33 +00:00
Chris Lattner
42cf317fca Two changes:
* In promote32, if we can just promote a constant value, do so instead of
    promoting a constant dynamically.
  * In visitReturn inst, actually USE the promote32 argument that takes a
    Value*

The end result of this is that we now generate this:

test:
        mov %EAX, 0
        ret

instead of...

test:
        mov %AX, 0
        movzx %EAX, %AX
        ret

for:

ushort %test() {
        ret ushort 0
}

llvm-svn: 12679
2004-04-06 01:21:00 +00:00
Chris Lattner
9236135e8f Support getelementptr instructions which use uint's to index into structure
types and can have arbitrary 32- and 64-bit integer types indexing into
sequential types.

llvm-svn: 12653
2004-04-05 01:30:19 +00:00
Alkis Evlogimenos
27ed33c309 Clean up code a bit.
llvm-svn: 12615
2004-04-02 18:11:32 +00:00
Alkis Evlogimenos
85e007a6dc Fix type in comments
llvm-svn: 12611
2004-04-02 16:02:50 +00:00
Alkis Evlogimenos
84ee10f9e1 Fix type in instruction builder instantiation
llvm-svn: 12610
2004-04-02 15:51:03 +00:00
Alkis Evlogimenos
20b074682c Add more ADC and SBB variants
llvm-svn: 12607
2004-04-02 07:11:10 +00:00
Chris Lattner
b6e4e5a95e Simplify code by using the more powerful BuildMI forms.
Implement a small optimization.  In test/Regression/CodeGen/X86/select.ll,
we now generate this for foldSel3:

foldSel3:
        mov %AL, BYTE PTR [%ESP + 4]
        fld DWORD PTR [%ESP + 8]
        fld DWORD PTR [%ESP + 12]
        mov %EAX, DWORD PTR [%ESP + 16]
        mov %ECX, DWORD PTR [%ESP + 20]
        cmp %EAX, %ECX
        fxch %ST(1)
        fcmovae %ST(0), %ST(1)
***     fstp %ST(1)
        ret

Instead of:

foldSel3:
        mov %AL, BYTE PTR [%ESP + 4]
        fld DWORD PTR [%ESP + 8]
        fld DWORD PTR [%ESP + 12]
        mov %EAX, DWORD PTR [%ESP + 16]
        mov %ECX, DWORD PTR [%ESP + 20]
        cmp %EAX, %ECX
        fxch %ST(1)
        fcmovae %ST(0), %ST(1)
***     fxch %ST(1)
***     fstp %ST(0)
        ret

In practice, this only effects code size: performance should be basically
unaffected.

llvm-svn: 12588
2004-04-01 04:06:09 +00:00
Chris Lattner
78027ca4ff Wrap at 80 cols
llvm-svn: 12587
2004-04-01 04:03:27 +00:00
Chris Lattner
2e0755a058 Generate slightly smaller code, "test R, R" instead of "cmp R, 0"
llvm-svn: 12579
2004-03-31 22:22:36 +00:00
Chris Lattner
97e8b80649 The X86 backend no longer needs the select lowering pass.
llvm-svn: 12578
2004-03-31 22:03:46 +00:00
Chris Lattner
e5d60adc20 Codegen FP select instructions into X86 conditional moves. Annoyingly enough
the X86 does not support a full set of fp cmove instructions, so we can't always
fold the condition into the select.  :(  Yuck.

llvm-svn: 12577
2004-03-31 22:03:35 +00:00
Chris Lattner
d50df93168 Add support for floating point conditional move instructions
llvm-svn: 12576
2004-03-31 22:02:36 +00:00
Chris Lattner
4d543b4201 Add support for FP cmoves
llvm-svn: 12575
2004-03-31 22:02:21 +00:00
Chris Lattner
e4fa3010db Add FP conditional move instructions, which annoyingly have special properties
that require the asmwriter to be extended (printing implicit uses before the
explicit operands)

llvm-svn: 12574
2004-03-31 22:02:13 +00:00
Chris Lattner
f477746a61 Fold comparisons into select instructions, making much better code and
using our broad selection of movcc instructions.  :)

llvm-svn: 12560
2004-03-30 22:39:09 +00:00
Chris Lattner
6c1dd729d3 Implement spill code folding for all of the conditional move instructions
llvm-svn: 12554
2004-03-30 21:29:47 +00:00
Chris Lattner
ff016bd6fe Add direct support for integer select instructions, though we still don't support
folding compares into the select yet.

llvm-svn: 12553
2004-03-30 21:22:00 +00:00
Chris Lattner
57968a98df Fix some serious bugs in the cmov descriptions, which didn't cause a problem because
we never generated them

Make indentation a bit more consistent

llvm-svn: 12549
2004-03-30 20:18:02 +00:00
Chris Lattner
95942c021a Fix a fairly major performance problem. If a PHI node had a constant as
an incoming value from a block, the selector would evaluate the constant
at the TOP of the block instead of at the end of the block.  This made the
live range for the constant span the entire block, increasing register
pressure needlessly.

llvm-svn: 12542
2004-03-30 19:10:12 +00:00
Chris Lattner
87479998f2 Add the select lowering pass to get initial support for select instructions
llvm-svn: 12541
2004-03-30 18:41:59 +00:00
Chris Lattner
b8f179cb9b Malloc doesn't kill a load. This patch need not go into 1.2 though.
llvm-svn: 12500
2004-03-18 17:01:26 +00:00
Chris Lattner
ef7c1e9f7f Fix a really nasty bug that was breaking ijpeg in LLC mode. We were incorrectly
folding load instructions into other instructions across free instruction
boundaries.  Perhaps this will also fix the other strange failures?

llvm-svn: 12494
2004-03-18 06:29:54 +00:00
Alkis Evlogimenos
6ac147a7fb Add LAHF instruction
llvm-svn: 12424
2004-03-15 17:20:14 +00:00
Alkis Evlogimenos
2b94b048a9 Another API change to MRegisterInfo::foldMemoryOperand. Instead of a
MachineBasicBlock::iterator take a MachineInstr*.

llvm-svn: 12392
2004-03-14 20:14:27 +00:00
Alkis Evlogimenos
ff9482b664 Change MRegisterInfo::foldMemoryOperand to return the folded
instruction to make the API more flexible.

llvm-svn: 12386
2004-03-14 07:19:51 +00:00
Chris Lattner
b45245327e It helps if I save the file. :)
llvm-svn: 12357
2004-03-13 00:24:52 +00:00
Chris Lattner
f7bc6fd913 Rename the intrinsic enum values for llvm.va_* from Intrinsic::va_* to
Intrinsic::va*.  This avoid conflicting with macros in the stdlib.h file.

llvm-svn: 12356
2004-03-13 00:24:00 +00:00
Alkis Evlogimenos
da990ad8a4 Add support for a wider range of CMOV instructions.
llvm-svn: 12336
2004-03-12 17:59:56 +00:00
Misha Brukman
992e44e3c5 Fix compilation on Sparc: assert(0) => abort()
llvm-svn: 12289
2004-03-11 19:08:24 +00:00
Alkis Evlogimenos
a13672fd71 Check if printing of implicit uses is required for all types of shift
instructions.

llvm-svn: 12258
2004-03-09 06:10:15 +00:00
Alkis Evlogimenos
7c0224327e Differentiate between extended precision floats (80-bit) and double precision floats (64-bit)
llvm-svn: 12254
2004-03-09 03:37:54 +00:00
Alkis Evlogimenos
f86d2df13d Use newly added API to emit bytes for instructions that gas misassembles
llvm-svn: 12253
2004-03-09 03:35:34 +00:00
Alkis Evlogimenos
085957be0b Add emitInstruction() API so that we can get the bytes of a simple instruction
llvm-svn: 12252
2004-03-09 03:34:53 +00:00
Alkis Evlogimenos
813daf05c3 Constify things a bit
llvm-svn: 12251
2004-03-09 03:30:12 +00:00
Chris Lattner
a55628694a Implement folding explicit load instructions into binary operations. For a
testcase like this:

int %test(int* %P, int %A) {
        %Pv = load int* %P
        %B = add int %A, %Pv
        ret int %B
}

We now generate:
test:
        mov %ECX, DWORD PTR [%ESP + 4]
        mov %EAX, DWORD PTR [%ESP + 8]
        add %EAX, DWORD PTR [%ECX]
        ret

Instead of:
test:
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %ECX, DWORD PTR [%ESP + 8]
        mov %EAX, DWORD PTR [%EAX]
        add %EAX, %ECX
        ret

... saving one instruction, and often a register.  Note that there are a lot
of other instructions that could use this, but they aren't handled.  I'm not
really interested in adding them, but mul/div and all of the FP instructions
could be supported as well if someone wanted to add them.

llvm-svn: 12204
2004-03-08 01:58:35 +00:00
Chris Lattner
9a9b1c4822 Rearrange and refactor some code. No functionality changes.
llvm-svn: 12203
2004-03-08 01:18:36 +00:00