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2793 Commits

Author SHA1 Message Date
Andrew Lenharth
f5b9a8fe57 Let me introduce you to the early stages of the llvm backend for the alpha processor 
llvm-svn: 19764
 2005-01-22 23:41:55 +00:00
Chris Lattner
b4cf4ffb04 Speed up folding operations into loads. 
llvm-svn: 19733
 2005-01-21 21:43:02 +00:00
Chris Lattner
fd4d7f71ae The ever-important vanity pass name :) 
llvm-svn: 19731
 2005-01-21 21:35:14 +00:00
Chris Lattner
5f2fbeaa69 Fix a FIXME: realize that argument stores are all independent (don't alias) 
llvm-svn: 19728
 2005-01-21 19:46:38 +00:00
Chris Lattner
febeb380ae Implement ADD_PARTS/SUB_PARTS so that 64-bit integer add/sub work. This 
fixes most of the remaining llc-beta failures.

llvm-svn: 19716
 2005-01-20 18:53:00 +00:00
Chris Lattner
8b0a2a3251 Fix a crash compiling 134.perl. 
llvm-svn: 19711
 2005-01-20 16:50:16 +00:00
Chris Lattner
6534e1ede3 Fix a problem where were were literally selecting for INCREASED register 
pressure, not decreases register pressure.  Fix problem where we accidentally
swapped the operands of SHLD, which caused fourinarow to fail.  This fixes
fourinarow.

llvm-svn: 19697
 2005-01-19 17:24:34 +00:00
Chris Lattner
b75589131d When commuting these instructions, make sure to actually swap the operands too. 
llvm-svn: 19694
 2005-01-19 16:55:52 +00:00
Chris Lattner
fde1a5688b Implement Regression/CodeGen/X86/rotate.ll: emit rotate instructions (which 
typically cost 1 cycle) instead of shld/shrd instruction (which are typically
6 or more cycles).  This also saves code space.

For example, instead of emitting:

rotr:
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %CL, BYTE PTR [%ESP + 8]
        shrd %EAX, %EAX, %CL
        ret
rotli:
        mov %EAX, DWORD PTR [%ESP + 4]
        shrd %EAX, %EAX, 27
        ret

Emit:

rotr32:
        mov %CL, BYTE PTR [%ESP + 8]
        mov %EAX, DWORD PTR [%ESP + 4]
        ror %EAX, %CL
        ret
rotli32:
        mov %EAX, DWORD PTR [%ESP + 4]
        ror %EAX, 27
        ret

We also emit byte rotate instructions which do not have a sh[lr]d counterpart
at all.

llvm-svn: 19692
 2005-01-19 08:07:05 +00:00
Chris Lattner
34757ff939 Add rotate instructions. 
llvm-svn: 19690
 2005-01-19 07:50:03 +00:00
Chris Lattner
e539ce8223 Match 16-bit shld/shrd instructions as well, implementing shift-double.llx:test5 
llvm-svn: 19689
 2005-01-19 07:37:26 +00:00
Chris Lattner
9d5ee289d7 Improve coverage of the X86 instruction set by adding 16-bit shift doubles. 
llvm-svn: 19687
 2005-01-19 07:31:24 +00:00
Chris Lattner
c03f360215 Teach the code generator that shrd/shld is commutable if it has an immediate. 
This allows us to generate this:

foo:
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %EDX, DWORD PTR [%ESP + 8]
        shld %EDX, %EDX, 2
        shl %EAX, 2
        ret

instead of this:

foo:
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %ECX, DWORD PTR [%ESP + 8]
        mov %EDX, %EAX
        shrd %EDX, %ECX, 30
        shl %EAX, 2
        ret

Note the magically transmogrifying immediate.

llvm-svn: 19686
 2005-01-19 07:11:01 +00:00
Chris Lattner
33efebcdc8 Finegrainify namespacification 
Add default impl of commuteInstruction
Add notes about ugly V9 code.

llvm-svn: 19684
 2005-01-19 06:53:34 +00:00
Chris Lattner
575e912fcf Codegen long >> 2 to this: 
foo:
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %EDX, DWORD PTR [%ESP + 8]
        shrd %EAX, %EDX, 2
        sar %EDX, 2
        ret

instead of this:

test1:
        mov %ECX, DWORD PTR [%ESP + 4]
        shr %ECX, 2
        mov %EDX, DWORD PTR [%ESP + 8]
        mov %EAX, %EDX
        shl %EAX, 30
        or %EAX, %ECX
        sar %EDX, 2
        ret

and long << 2 to this:

foo:
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %ECX, DWORD PTR [%ESP + 8]
***     mov %EDX, %EAX
        shrd %EDX, %ECX, 30
        shl %EAX, 2
        ret

instead of this:

foo:
        mov %EAX, DWORD PTR [%ESP + 4]
        mov %ECX, %EAX
        shr %ECX, 30
        mov %EDX, DWORD PTR [%ESP + 8]
        shl %EDX, 2
        or %EDX, %ECX
        shl %EAX, 2
        ret

The extra copy (marked ***) can be eliminated when I teach the code generator
that shrd32rri8 is really commutative.

llvm-svn: 19681
 2005-01-19 06:18:43 +00:00
Chris Lattner
419a5d213b X86 shifts mask the amount. 
llvm-svn: 19678
 2005-01-19 03:36:30 +00:00
Chris Lattner
fbd1f8e4fd Add a hook to find out how the target handles shift amounts that are out of 
range.  Either they are undefined (the default), they mask the shift amount
to the size of the register (X86, Alpha, etc), or they extend the shift (PPC).

This defaults to undefined, which is conservatively correct.

llvm-svn: 19677
 2005-01-19 03:36:14 +00:00
Chris Lattner
6dec8cb829 Code to handle FP_EXTEND is dead now. X86 doesn't support any data types to 
FP_EXTEND from!

llvm-svn: 19674
 2005-01-18 20:05:56 +00:00
Chris Lattner
798e9c85d6 Remove more dead code. 
llvm-svn: 19673
 2005-01-18 19:50:08 +00:00
Chris Lattner
401814508f The selection dag code handles the promotions from F32 to F64 for us, so we 
don't need to even think about F32 in the X86 code anymore.

llvm-svn: 19672
 2005-01-18 19:46:54 +00:00
Chris Lattner
dc09e52b3e Fix 124.m88ksim. 
llvm-svn: 19667
 2005-01-18 17:35:28 +00:00
Chris Lattner
a04b1ee7a8 Do not emit loads multiple times, potentially in the wrong places. 
llvm-svn: 19661
 2005-01-18 04:18:32 +00:00
Tanya Lattner
d3459278f2 Minor changes. 
llvm-svn: 19660
 2005-01-18 04:15:41 +00:00
Chris Lattner
722ddeb86e Eliminate bad assertions. 
llvm-svn: 19659
 2005-01-18 04:00:54 +00:00
Chris Lattner
8f3a8d96e2 * Eliminate the TokenSet and just use the ExprMap for both tokens and values. 
* Insert some really pedantic assertions that will notice when we emit the
  same loads more than one time, exposing bugs.  This turns a miscompilation in
  bzip2 into a compile-fail.  yaay.

llvm-svn: 19658
 2005-01-18 03:51:59 +00:00
Chris Lattner
b3edb09ede Rely on the code in MatchAddress to do this work. Otherwise we fail to 
match (X+Y)+(Z << 1), because we match the X+Y first, consuming the index
register, then there is no place to put the Z.

llvm-svn: 19652
 2005-01-18 02:25:52 +00:00
Chris Lattner
ce2e0125dc Fix a problem where probing for addressing modes caused expressions to be 
emitted too early.  In particular, this fixes
Regression/CodeGen/X86/regpressure.ll:regpressure3.

This also improves the 2nd basic block in 164.gzip:flush_block, which went from

.LBBflush_block_1:      # loopentry.1.i
        movzx %EAX, WORD PTR [dyn_ltree + 20]
        movzx %ECX, WORD PTR [dyn_ltree + 16]
        mov DWORD PTR [%ESP + 32], %ECX
        movzx %ECX, WORD PTR [dyn_ltree + 12]
        movzx %EDX, WORD PTR [dyn_ltree + 8]
        movzx %EBX, WORD PTR [dyn_ltree + 4]
        mov DWORD PTR [%ESP + 36], %EBX
        movzx %EBX, WORD PTR [dyn_ltree]
        add DWORD PTR [%ESP + 36], %EBX
        add %EDX, DWORD PTR [%ESP + 36]
        add %ECX, %EDX
        add DWORD PTR [%ESP + 32], %ECX
        add %EAX, DWORD PTR [%ESP + 32]
        movzx %ECX, WORD PTR [dyn_ltree + 24]
        add %EAX, %ECX
        mov %ECX, 0
        mov %EDX, %ECX

to

.LBBflush_block_1:      # loopentry.1.i
        movzx %EAX, WORD PTR [dyn_ltree]
        movzx %ECX, WORD PTR [dyn_ltree + 4]
        add %ECX, %EAX
        movzx %EAX, WORD PTR [dyn_ltree + 8]
        add %EAX, %ECX
        movzx %ECX, WORD PTR [dyn_ltree + 12]
        add %ECX, %EAX
        movzx %EAX, WORD PTR [dyn_ltree + 16]
        add %EAX, %ECX
        movzx %ECX, WORD PTR [dyn_ltree + 20]
        add %ECX, %EAX
        movzx %EAX, WORD PTR [dyn_ltree + 24]
        add %ECX, %EAX
        mov %EAX, 0
        mov %EDX, %EAX

... which results in less spilling in the function.

This change alone speeds up 164.gzip from 37.23s to 36.24s on apoc.  The
default isel takes 37.31s.

llvm-svn: 19650
 2005-01-18 01:06:26 +00:00
Chris Lattner
a78f9ced61 Fix indentation. 
llvm-svn: 19649
 2005-01-17 23:25:45 +00:00
Chris Lattner
dff1e3e86f Don't bother using max here. 
llvm-svn: 19647
 2005-01-17 23:02:13 +00:00
Chris Lattner
2d86b43318 Do not give token factor nodes outrageous weights 
llvm-svn: 19645
 2005-01-17 22:56:09 +00:00
Chris Lattner
f2878ce8ba Two changes: 
1. Fold  [mem] += (1|-1) into inc [mem]/dec [mem] to save some icache space.
 2. Do not let token factor nodes prevent forming '[mem] op= val' folds.

llvm-svn: 19643
 2005-01-17 22:10:42 +00:00
Chris Lattner
40c0fca632 Refactor load/op/store folding into it's own method, no functionality changes. 
llvm-svn: 19641
 2005-01-17 19:25:26 +00:00
Chris Lattner
2348abc421 Fix a major regression last night that prevented us from producing [mem] op= reg 
operations.

The body of the if is less indented but unmodified in this patch.

llvm-svn: 19638
 2005-01-17 17:49:14 +00:00
Chris Lattner
adb669ab1f Codegen this: 
int %foo(int %X) {
        %T = add int %X, 13
        %S = mul int %T, 3
        ret int %S
}

as this:

        mov %ECX, DWORD PTR [%ESP + 4]
        lea %EAX, DWORD PTR [%ECX + 2*%ECX + 39]
        ret

instead of this:

        mov %ECX, DWORD PTR [%ESP + 4]
        mov %EAX, %ECX
        add %EAX, 13
        imul %EAX, %EAX, 3
        ret

llvm-svn: 19633
 2005-01-17 06:48:02 +00:00
Tanya Lattner
5a10531cf8 Added tmp instructions to preserve ssa. 
llvm-svn: 19632
 2005-01-17 06:47:26 +00:00
Chris Lattner
51590b615c Fix test/Regression/CodeGen/X86/2005-01-17-CycleInDAG.ll and 132.ijpeg. 
Do not fold a load into an operation if it will induce a cycle in the DAG.

Repeat after me: dAg.

llvm-svn: 19631
 2005-01-17 06:26:58 +00:00
Chris Lattner
f1e85bec5a Do not fold a load into a comparison that is used by more than one place. 
The comparison will probably be folded, so this is not ok to do.
This fixed 197.parser.

llvm-svn: 19624
 2005-01-17 01:34:14 +00:00
Chris Lattner
1b8c8fe020 Do not codegen 'xor bool, true' as 'not reg'. not reg inverts the upper bits 
of the bytereg.  This fixes yacr2, 300.twolf and probably others.

llvm-svn: 19622
 2005-01-17 00:23:16 +00:00
Chris Lattner
46dac4394c Set up the shift and setcc types. 
If we emit a load because we followed a token chain to get to it, try to
fold it into its single user if possible.

llvm-svn: 19620
 2005-01-17 00:00:33 +00:00
Chris Lattner
4c88cc95ee Shift and setcc types default to the pointer type. 
llvm-svn: 19619
 2005-01-16 23:59:48 +00:00
Tanya Lattner
fea188af7e Added paramters to a few functions in order to allow me to change the functions to preserve SSA 
llvm-svn: 19615
 2005-01-16 08:51:10 +00:00
Chris Lattner
9ffc59287e * Adjust to changes in TargetLowering interfaces. 
* Remove custom promotion for bool and byte select ops.  Legalize now
  promotes them for us.
* Allow folding ConstantPoolIndexes into EXTLOAD's, useful for float immediates.
* Declare which operations are not supported better.
* Add some hacky code for TRUNCSTORE to pretend that we have truncstore
  for i16 types.  This is useful for testing promotion code because I can
  just remove 16-bit registers all together and verify that programs work.

llvm-svn: 19614
 2005-01-16 07:34:08 +00:00
Chris Lattner
b49d2a7b0f Use enums, move virtual dtor out of line. 
llvm-svn: 19610
 2005-01-16 07:28:11 +00:00
Chris Lattner
be2a427f51 cycles_t -> CycleCount_t 
llvm-svn: 19604
 2005-01-16 04:20:30 +00:00
Reid Spencer
afa1cb9e11 Rename BUILD_* to PROJ_* 
llvm-svn: 19592
 2005-01-16 02:21:29 +00:00
Tanya Lattner
66cf1a6f82 Fixed a couple of instructions that broke SSA. 
llvm-svn: 19587
 2005-01-16 02:14:17 +00:00
Chris Lattner
605b9a23a2 Improve compatiblity with HPUX on Itanium, patch by Duraid Madina 
llvm-svn: 19586
 2005-01-16 01:31:31 +00:00
Chris Lattner
06c297f8ca Set up identity transforms. 
llvm-svn: 19584
 2005-01-16 01:20:18 +00:00
Chris Lattner
1d0e1ffe02 Move some information out of LegalizeDAG into the generic Target interface. 
llvm-svn: 19581
 2005-01-16 01:10:58 +00:00
Chris Lattner
98611ce291 Add a new target-independent code generator flag. 
llvm-svn: 19567
 2005-01-15 06:00:32 +00:00
Chris Lattner
f3d950e816 Add support for truncstore and *extload. 
llvm-svn: 19566
 2005-01-15 05:22:24 +00:00
Chris Lattner
27c91fac94 Adjust to CopyFromREg changes. 
llvm-svn: 19561
 2005-01-14 22:37:41 +00:00
Chris Lattner
c032990335 Fix Regression/CodeGen/PowerPC/2005-01-14-UndefLong.ll 
llvm-svn: 19557
 2005-01-14 20:22:02 +00:00
Chris Lattner
b0b49268c4 Fix: Regression/CodeGen/PowerPC/2005-01-14-SetSelectCrash.ll 
llvm-svn: 19555
 2005-01-14 19:31:00 +00:00
Chris Lattner
7a8788c9ac Add new ImplicitDef node, rename CopyRegSDNode class to RegSDNode. 
llvm-svn: 19535
 2005-01-13 20:50:02 +00:00
Chris Lattner
fce6a5439d Codegen factor nodes more intelligently according to perceived register pressure. 
llvm-svn: 19532
 2005-01-13 19:56:00 +00:00
Chris Lattner
cb4359465a Initial trivial (but stupid) codegen for this node. 
llvm-svn: 19529
 2005-01-13 18:01:36 +00:00
Chris Lattner
9a70166615 Add some really pedantic assertions to the load folding code. Fix a bunch 
of cases where we accidentally emitted a load folded once and unfolded
elsewhere.

llvm-svn: 19522
 2005-01-13 05:53:16 +00:00
Chris Lattner
2ab70aafe0 We can only fold a load into an op if there is exactly one use of the value. 
Checking to see if the load has two uses is not equivalent, as the chain
value may have zero uses.

llvm-svn: 19518
 2005-01-12 18:38:26 +00:00
Chris Lattner
4b03f0f99e Try both ways to fold an add together. This allows us to generate this code 
imul %EAX, %EAX, 400
        add %ECX, %EAX
        add %ESI, DWORD PTR [%ECX + 4*%EDX]
        inc %EDX
        cmp %EDX, 100

instead of this:

        imul %EAX, %EAX, 400
        add %ECX, %EAX
        mov %EAX, %EDX
        shl %EAX, 2
        add %ECX, %EAX
        add %ESI, DWORD PTR [%ECX]
        inc %EDX
        cmp %EDX, 100

llvm-svn: 19513
 2005-01-12 18:08:53 +00:00
Chris Lattner
61c572eb7f Fix a major miscompilation where we were overwriting the scale reg. 
llvm-svn: 19511
 2005-01-12 07:33:20 +00:00
Chris Lattner
5816f1a302 Do not use the type of the RHS constant to determine the type of the operation. 
This fails for shifts because the constant is always 8 bits.

llvm-svn: 19508
 2005-01-12 05:22:07 +00:00
Chris Lattner
89d6b21ae6 Do not lose the offset from teh global when peephole optimizing instructions. 
This fixes FreeBench/pcompress

llvm-svn: 19507
 2005-01-12 05:17:28 +00:00
Jeff Cohen
614a5ec22a Fix C++ more compilatiom errors 
llvm-svn: 19504
 2005-01-12 04:29:05 +00:00
Chris Lattner
5ef92f3a40 Fix a compile error with VC++, which things that static const arrays need 
to be dynamically initialized. :(

llvm-svn: 19503
 2005-01-12 04:23:22 +00:00
Chris Lattner
627c64e5e5 Fix a bug that caused us to crash on povray. We weren't emitting an FP_REG_KILL into a block that had a successor with a FP PHI node. 
llvm-svn: 19502
 2005-01-12 04:21:28 +00:00
Chris Lattner
a5f0ba59a0 Print a load of a null pointer (in intel mode) like this: 
mov %AX, WORD PTR [0]

instead of like this:

        mov %AX, WORD PTR []

llvm-svn: 19501
 2005-01-12 04:07:11 +00:00
Chris Lattner
360988bae2 Print a load of a null pointer like this: 
movw 0, %ax

instead of like this:

        movw , %ax

llvm-svn: 19500
 2005-01-12 04:05:19 +00:00
Chris Lattner
3c85c67c97 Fix a crash compiling povray on UINT_TO_FP from i16. 
llvm-svn: 19499
 2005-01-12 04:00:00 +00:00
Chris Lattner
4e72a2a000 There are no [mem] op= reg instructions for FP, so remove their entries. 
llvm-svn: 19496
 2005-01-12 03:16:09 +00:00
Chris Lattner
00cb0ace9b Fix a bug where we didn't insert FP_REG_KILL instructions into MBB's that 
contain FP PHI nodes but no other FP defining instructions.  This fixes
183.equake

llvm-svn: 19495
 2005-01-12 02:57:10 +00:00
Chris Lattner
92166ed1df Fold TRUNCATE (LOAD P) into a smaller load from P. 
llvm-svn: 19494
 2005-01-12 02:19:06 +00:00
Chris Lattner
258b23bd9d Be more careful about order of arg evalution for CopyToReg nodes. This shrinks 
256.bzip2 from 7142 to 7103 lines of .s file.

Second, add initial support for folding loads into compares, though this code
is dynamically dead for now. :(

llvm-svn: 19493
 2005-01-12 02:02:48 +00:00
Chris Lattner
604416e8f4 Fold some more [mem] op= val operators. This allows us to things like this 
several times in 256.bzip2:

        mov %EAX, DWORD PTR [%ESP + 204]
-       mov %EAX, DWORD PTR [%EAX]
-       or %EAX, 2097152
-       mov %ECX, DWORD PTR [%ESP + 204]
-       mov DWORD PTR [%ECX], %EAX
+       or DWORD PTR [%EAX], 2097152

llvm-svn: 19492
 2005-01-12 01:28:00 +00:00
Chris Lattner
e83ae1063f Fold loads into sign/zero extends. instead of: 
mov %AL, BYTE PTR [%EDX + l18_length_code]
  movzx %EAX, %AL

Emit:

  movzx %EAX, BYTE PTR [%EDX + l18_length_code]

llvm-svn: 19489
 2005-01-11 23:33:00 +00:00
Chris Lattner
87a38bd4a8 Comment out debug code :) 
Select [mem] += Val operations.  For constants, we used to get:

  mov %ECX, -32768
  add %ECX, DWORD PTR [l4_match_start]
  mov DWORD PTR [l4_match_start], %ECX

Now we get:

  add DWORD PTR [l4_match_start], -32768

For other values we used to get:

  mov %EBP, %EDI   ;; because the add destroys the value
  add %EBP, DWORD PTR [l4_input_len]
  mov DWORD PTR [l4_input_len], %EBP

now we get:

  add DWORD PTR [l4_input_len], %EDI

Both of these use less registers than the alternative, are faster and smaller.

llvm-svn: 19488
 2005-01-11 23:21:30 +00:00
Chris Lattner
282473a25d Handle the global address case here, not just the offset case. 
llvm-svn: 19487
 2005-01-11 22:58:43 +00:00
Chris Lattner
9eb2cc700b Treat int constants as not requiring a register, since they are almost always 
folded into an instruction.

llvm-svn: 19486
 2005-01-11 22:29:12 +00:00
Chris Lattner
7cb2220907 * Factor a bunch of binary operator cases into shared code. 
* Fold loads into Add, sub, and, or, xor and mul when possible.
* Codegen shl X, 1 as add X, X

llvm-svn: 19483
 2005-01-11 21:19:59 +00:00
Chris Lattner
b1a72cb39a Clear the whole array, always. 
llvm-svn: 19482
 2005-01-11 20:25:26 +00:00
Chris Lattner
b838c9748e Fold multiplies by 3,5,9 into addressing modes when possible. 
llvm-svn: 19480
 2005-01-11 19:37:02 +00:00
Chris Lattner
e7b1130b01 Instead of generating stuff like this: 
mov %ECX, %EAX
        add %ECX, 32768
        mov %SI, WORD PTR [2*%ECX + l13_prev]

Generate this:

        mov %SI, WORD PTR [2*%ECX + l13_prev + 65536]

This occurs when you have a GEP instruction where an index is
"something + imm".

llvm-svn: 19472
 2005-01-11 06:36:20 +00:00
Chris Lattner
bb63a09cd1 Implement MEMCPY natively in terms of rep movs* 
llvm-svn: 19468
 2005-01-11 06:19:26 +00:00
Chris Lattner
b2b08a8bc1 Implement memset -> rep stos* 
llvm-svn: 19467
 2005-01-11 06:14:36 +00:00
Chris Lattner
58816a9e81 Announce that we don't support mem ops yet. 
llvm-svn: 19466
 2005-01-11 05:57:36 +00:00
Chris Lattner
f867443d7e Teach the address selector to make 'reg+reg' addressing modes. 
llvm-svn: 19457
 2005-01-11 04:40:19 +00:00
Chris Lattner
edf06be50e Emit NOT instructions. 
llvm-svn: 19455
 2005-01-11 04:31:30 +00:00
Chris Lattner
4e4bef2d6c Fix a bug emitting branches that broke a lot of programs. 
llvm-svn: 19452
 2005-01-11 04:06:27 +00:00
Chris Lattner
4b51297a94 Be more careful where we set ContainsFPCode. We were missing a set in the 
int -> FP casting code.  Note that we don't have to set it for FP operations
that take FP values as operands: whatever produces the FP value will set the
flag.

llvm-svn: 19451
 2005-01-11 03:50:45 +00:00
Chris Lattner
0c4c4094e3 Fix a major bug in setcc/cmov folding, where we accidentally 
inverted the sense of the comparison.

llvm-svn: 19450
 2005-01-11 03:37:59 +00:00
Chris Lattner
d188e03011 Take register pressure into account when we have to decide whether to 
evaluate the LHS or the RHS of an operation first.  This causes good things
to happen.  For example, instead of compiling a loop to this:

.LBBstrength_result7_1: # loopentry
        movl 16(%esp), %edi
        movl (%edi), %edi             ;;; LOAD
        movl (%ecx), %ebx
        movl $2, (%eax,%ebx,4)
        movl (%edx), %ebx
        movl %esi, %ebp
        addl $21, %ebp
        addl $42, %esi
        cmpl $0, %edi                 ;;; USE
        cmovne %esi, %ebp
        cmpl %ebp, %ebx
        movl %ebp, %esi
        jg .LBBstrength_result7_1

We now compile it to this:

.LBBstrength_result7_1: # loopentry
        movl %edi, %ebx
        addl $42, %ebx
        addl $21, %edi
        movl (%ecx), %ebp              ;; LOAD
        cmpl $0, %ebp                  ;; USE
        cmovne %ebx, %edi
        movl (%edx), %ebx
        movl $2, (%eax,%ebx,4)
        movl (%esi), %ebx
        cmpl %edi, %ebx
        jg .LBBstrength_result7_1

Which reduces register pressure enough (in this case) to avoid spilling in the
loop.

As another example, consider the CodeGen/X86/regpressure.ll testcase.  We
used to generate this code for both cases:

regpressure1:
        subl $32, %esp
        movl %esi, 12(%esp)
        movl %edi, 8(%esp)
        movl %ebx, 4(%esp)
        movl %ebp, (%esp)
        movl 36(%esp), %ecx
        movl (%ecx), %eax
        movl 4(%ecx), %edx
        movl %edx, 24(%esp)
        movl 8(%ecx), %edx
        movl %edx, 16(%esp)
        movl 12(%ecx), %edx
        movl 16(%ecx), %esi
        movl 20(%ecx), %edi
        movl 24(%ecx), %ebx
        movl %ebx, 28(%esp)
        movl 28(%ecx), %ebx
        movl 32(%ecx), %ebp
        movl %ebp, 20(%esp)
        movl 36(%ecx), %ecx
        imull 24(%esp), %eax
        imull 16(%esp), %eax
        imull %edx, %eax
        imull %esi, %eax
        imull %edi, %eax
        imull 28(%esp), %eax
        imull %ebx, %eax
        imull 20(%esp), %eax
        imull %ecx, %eax
        movl (%esp), %ebp
        movl 4(%esp), %ebx
        movl 8(%esp), %edi
        movl 12(%esp), %esi
        addl $32, %esp
        ret

This code is basically trying to do all of the loads first, then execute all
of the multiplies.  Because we run out of registers, lots of spill code happens.
We now generate this code for both cases:

regpressure1:
        movl 4(%esp), %ecx
        movl (%ecx), %eax
        movl 4(%ecx), %edx
        imull %edx, %eax
        movl 8(%ecx), %edx
        imull %edx, %eax
        movl 12(%ecx), %edx
        imull %edx, %eax
        movl 16(%ecx), %edx
        imull %edx, %eax
        movl 20(%ecx), %edx
        imull %edx, %eax
        movl 24(%ecx), %edx
        imull %edx, %eax
        movl 28(%ecx), %edx
        imull %edx, %eax
        movl 32(%ecx), %edx
        imull %edx, %eax
        movl 36(%ecx), %ecx
        imull %ecx, %eax
        ret

which is much nicer (when we fold loads into the muls it will be even better).
The old instruction selector used to produce the good code for regpressure1
but not for regpressure2, as it depended on the order of operations in the
LLVM code.

llvm-svn: 19449
 2005-01-11 03:11:44 +00:00
Chris Lattner
497e24c885 Fold setcc instructions into selects. 
llvm-svn: 19438
 2005-01-10 22:10:13 +00:00
Chris Lattner
65d007ab62 Add conditional moves for the parity flag. 
llvm-svn: 19437
 2005-01-10 22:09:33 +00:00
Chris Lattner
d61491dea2 Implement 8-bit multiply for X86. 
llvm-svn: 19435
 2005-01-10 20:55:48 +00:00
Chris Lattner
fcab5f75c0 Codegen (Reg|imm)+&GV as an LEA, because we cannot put it into the immediate field 
of an ADDri (due to current restrictions on MachineOperand :( ).  This allows
us to generate:

        leal Data+16000, %edx

instead of:

        movl $Data, %edx
        addl $16000, %edx

llvm-svn: 19420
 2005-01-09 20:20:29 +00:00
Chris Lattner
35375c11bf Fix copy and pasto's for FP -> Int. This fixes fldry 
llvm-svn: 19418
 2005-01-09 19:49:59 +00:00
Chris Lattner
45155a3dee Initial implementation of FP->INT and INT->FP casts 
Also, fix zero_extend from bool to i8, which fixes Shootout/objinst.

llvm-svn: 19414
 2005-01-09 18:52:44 +00:00
Chris Lattner
9ca9b20447 Fix a subtle bug involving constant expr casts from int to fp 
llvm-svn: 19410
 2005-01-09 01:49:29 +00:00
Chris Lattner
c5e53c07fd Implement varargs and returnaddress/frameaddress intrinsics. With this 
patch, all of SingleSource/UnitTests passes.

llvm-svn: 19408
 2005-01-09 00:01:27 +00:00
Chris Lattner
ca81756527 Okay 15th time is the charm. Looking at the vector size is useless as it 
gets clobbered by a previous statement.  This fixes all calls finally.

llvm-svn: 19399
 2005-01-08 20:51:36 +00:00