Commit Graph

116 Commits

Author SHA1 Message Date
Chris Lattner 6777b72659 Add some notes about better flag handling.
llvm-svn: 41808
2007-09-10 21:43:18 +00:00
Chris Lattner 92c6a65d4e new example
llvm-svn: 41318
2007-08-23 15:16:03 +00:00
Chris Lattner 075b4db621 add a note
llvm-svn: 35530
2007-03-31 07:06:25 +00:00
Chris Lattner 26ad3e7191 add a note
llvm-svn: 35334
2007-03-25 05:10:46 +00:00
Chris Lattner 9c9e2f1af2 add a note
llvm-svn: 35330
2007-03-25 04:46:28 +00:00
Chris Lattner c9088b4c8e add a note
llvm-svn: 34101
2007-02-09 17:38:01 +00:00
Nate Begeman ba52b94fa2 Remove fixed item
llvm-svn: 34081
2007-02-09 04:19:54 +00:00
Chris Lattner 37ebf9317b A relatively simple PPC optimization.
llvm-svn: 33709
2007-01-31 19:49:20 +00:00
Nate Begeman 17f250005a Update some of the llvm in the readme
llvm-svn: 33630
2007-01-29 21:21:22 +00:00
Chris Lattner 889d934d00 move contents of PR587 to here.
llvm-svn: 33333
2007-01-18 07:34:57 +00:00
Chris Lattner 542dfd5510 Rewrite the branch selector to be correct in the face of large functions.
The algorithm it used before wasn't 100% correct, we now use an iterative
expansion model.  This fixes assembler errors when compiling 403.gcc with
tail merging enabled.

Change the way the branch selector works overall: Now, the isel generates
PPC::BCC instructions (as it used to) directly, and these BCC instructions
are emitted to the output or jitted directly if branches don't need
expansion.  Only if branches need expansion are instructions rewritten
and created.  This should make branch select faster, and eliminates the
Bxx instructions from the .td file.

llvm-svn: 31837
2006-11-18 00:32:03 +00:00
Chris Lattner cd436327f1 add note about ugly codegen with preinc
llvm-svn: 31617
2006-11-10 01:33:53 +00:00
Chris Lattner be7033b346 add a note from viterbi
llvm-svn: 31506
2006-11-07 18:30:21 +00:00
Chris Lattner 28174f5a3a this doesn't occur any more in mason
llvm-svn: 31236
2006-10-27 22:02:19 +00:00
Chris Lattner 4c0cc53da1 the code in question is now:
cmpw cr0, r7, r3
        ble cr0, LBB1_5 ;bb25
LBB1_8: ;bb17
        cmpw cr0, r8, r5
        bgt cr0, LBB1_2 ;bb

which is just as good as crnand.

llvm-svn: 31235
2006-10-27 22:00:55 +00:00
Chris Lattner be131662c3 add note
llvm-svn: 30937
2006-10-13 20:20:58 +00:00
Nate Begeman d31efd190f Fold AND and ROTL more often
llvm-svn: 30577
2006-09-22 05:01:56 +00:00
Chris Lattner fba9e8f422 item done
llvm-svn: 30518
2006-09-20 06:41:56 +00:00
Chris Lattner f62f090ea1 This is already done
llvm-svn: 30512
2006-09-20 04:59:33 +00:00
Chris Lattner aa3926b7ea Two improvements:
1. Codegen this comparison:
     if (X == 0x8000)

as:

        cmplwi cr0, r3, 32768
        bne cr0, LBB1_2 ;cond_next

instead of:

        lis r2, 0
        ori r2, r2, 32768
        cmpw cr0, r3, r2
        bne cr0, LBB1_2 ;cond_next


2. Codegen this comparison:
      if (X == 0x12345678)

as:

        xoris r2, r3, 4660
        cmplwi cr0, r2, 22136
        bne cr0, LBB1_2 ;cond_next

instead of:

        lis r2, 4660
        ori r2, r2, 22136
        cmpw cr0, r3, r2
        bne cr0, LBB1_2 ;cond_next

llvm-svn: 30509
2006-09-20 04:25:47 +00:00
Chris Lattner ab33d350a7 Add a note that we should match rlwnm better
llvm-svn: 30508
2006-09-20 03:59:25 +00:00
Chris Lattner 2aa98e0363 add a note
llvm-svn: 30377
2006-09-14 20:56:30 +00:00
Chris Lattner 950dffaed6 Add a note
llvm-svn: 29139
2006-07-14 04:07:29 +00:00
Chris Lattner a7976d329e Implement Regression/CodeGen/PowerPC/bswap-load-store.ll by folding bswaps
into i16/i32 load/stores.

llvm-svn: 29089
2006-07-10 20:56:58 +00:00
Chris Lattner 6353807fdc Add a note about a note
llvm-svn: 28355
2006-05-17 19:02:25 +00:00
Nate Begeman ce6646c366 Yet more readme updating
llvm-svn: 28172
2006-05-08 20:54:02 +00:00
Nate Begeman 68a45419cc New note about something bad happening in target independent optimizers
llvm-svn: 28170
2006-05-08 20:08:28 +00:00
Nate Begeman 0eb8f2e496 Proving once again that I am not as smart as the compiler
llvm-svn: 28169
2006-05-08 19:09:24 +00:00
Nate Begeman 9b6d4c2968 Fold more shifts into inserts, and update the README
llvm-svn: 28168
2006-05-08 17:38:32 +00:00
Nate Begeman dc996b3f6c Update some stuff now that the new rlwimi code has gone in
llvm-svn: 28162
2006-05-08 02:52:38 +00:00
Chris Lattner 304bbf3b1d New note, Nate, please check to see if I'm full of it :)
llvm-svn: 28118
2006-05-05 05:36:15 +00:00
Chris Lattner 5879efe0c8 add a note, move an altivec todo to the altivec list.
llvm-svn: 27654
2006-04-13 16:48:00 +00:00
Chris Lattner acf1fc8a28 add a note
llvm-svn: 27360
2006-04-02 07:20:00 +00:00
Chris Lattner 22ec3e7b7e Split out altivec notes into their own README
llvm-svn: 27168
2006-03-27 07:04:16 +00:00
Chris Lattner 5d70a7c4a5 #include Intrinsics.h into all dag isels
llvm-svn: 27109
2006-03-25 06:47:10 +00:00
Chris Lattner 9f9b6116e1 add another note
llvm-svn: 27077
2006-03-24 20:04:27 +00:00
Chris Lattner cbcfe46556 add a note
llvm-svn: 27000
2006-03-23 21:28:44 +00:00
Chris Lattner eccf46950c This has been implemented. Tweak it into another note
llvm-svn: 26944
2006-03-22 05:33:23 +00:00
Nate Begeman 013127981a Update readme
llvm-svn: 26924
2006-03-21 18:58:20 +00:00
Chris Lattner f194834161 minor note
llvm-svn: 26912
2006-03-21 00:47:09 +00:00
Chris Lattner 169e6238ad Add a note about the MUL -> FMADD vector bug.
llvm-svn: 26874
2006-03-19 22:08:08 +00:00
Chris Lattner ea6468758d notes
llvm-svn: 26856
2006-03-19 05:33:30 +00:00
Nate Begeman bb01d4f272 Remove BRTWOWAY*
Make the PPC backend not dependent on BRTWOWAY_CC and make the branch
selector smarter about the code it generates, fixing a case in the
readme.

llvm-svn: 26814
2006-03-17 01:40:33 +00:00
Nate Begeman fb0e36fa56 Notes on how to kill the eeevil brtwoway, and make ppc branch selector
more target independant, generate better code, and be less conservative.

llvm-svn: 26809
2006-03-16 22:37:48 +00:00
Chris Lattner 325bb46315 add a note
llvm-svn: 26807
2006-03-16 22:25:55 +00:00
Nate Begeman 32e73f9881 Another case we could do better on.
llvm-svn: 26795
2006-03-16 18:50:44 +00:00
Chris Lattner a8dd636192 add a note
llvm-svn: 26605
2006-03-08 00:25:47 +00:00
Chris Lattner 883cefc656 add a note
llvm-svn: 26585
2006-03-07 04:42:59 +00:00
Chris Lattner 3cb349a068 add a note
llvm-svn: 26448
2006-03-01 06:36:20 +00:00
Chris Lattner 27f5345b1f Compile this:
void foo(float a, int *b) { *b = a; }

to this:

_foo:
        fctiwz f0, f1
        stfiwx f0, 0, r4
        blr

instead of this:

_foo:
        fctiwz f0, f1
        stfd f0, -8(r1)
        lwz r2, -4(r1)
        stw r2, 0(r4)
        blr

This implements CodeGen/PowerPC/stfiwx.ll, and also incidentally does the
right thing for GCC bugzilla 26505.

llvm-svn: 26447
2006-03-01 05:50:56 +00:00