Commit Graph

106 Commits

Author SHA1 Message Date
Chris Lattner
54e853b8a6 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31837 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-18 00:32:03 +00:00
Chris Lattner
26ddb506ec add note about ugly codegen with preinc
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31617 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-10 01:33:53 +00:00
Chris Lattner
6e11295b23 add a note from viterbi
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31506 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-07 18:30:21 +00:00
Chris Lattner
7a498cbc60 this doesn't occur any more in mason
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31236 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-27 22:02:19 +00:00
Chris Lattner
4ccf63d8cf 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31235 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-27 22:00:55 +00:00
Chris Lattner
6a250ecc99 add note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30937 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-13 20:20:58 +00:00
Nate Begeman
f42f133938 Fold AND and ROTL more often
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30577 91177308-0d34-0410-b5e6-96231b3b80d8
2006-09-22 05:01:56 +00:00
Chris Lattner
f142713a30 item done
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30518 91177308-0d34-0410-b5e6-96231b3b80d8
2006-09-20 06:41:56 +00:00
Chris Lattner
ac924c8248 This is already done
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30512 91177308-0d34-0410-b5e6-96231b3b80d8
2006-09-20 04:59:33 +00:00
Chris Lattner
3836dbd3bd 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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30509 91177308-0d34-0410-b5e6-96231b3b80d8
2006-09-20 04:25:47 +00:00
Chris Lattner
cc96ac3a7d Add a note that we should match rlwnm better
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30508 91177308-0d34-0410-b5e6-96231b3b80d8
2006-09-20 03:59:25 +00:00
Chris Lattner
f0613e1e7c add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30377 91177308-0d34-0410-b5e6-96231b3b80d8
2006-09-14 20:56:30 +00:00
Chris Lattner
1eeedaea59 Add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29139 91177308-0d34-0410-b5e6-96231b3b80d8
2006-07-14 04:07:29 +00:00
Chris Lattner
d998938459 Implement Regression/CodeGen/PowerPC/bswap-load-store.ll by folding bswaps
into i16/i32 load/stores.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29089 91177308-0d34-0410-b5e6-96231b3b80d8
2006-07-10 20:56:58 +00:00
Chris Lattner
9d62fa4d16 Add a note about a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28355 91177308-0d34-0410-b5e6-96231b3b80d8
2006-05-17 19:02:25 +00:00
Nate Begeman
7514620052 Yet more readme updating
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28172 91177308-0d34-0410-b5e6-96231b3b80d8
2006-05-08 20:54:02 +00:00
Nate Begeman
fcf64a91d6 New note about something bad happening in target independent optimizers
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28170 91177308-0d34-0410-b5e6-96231b3b80d8
2006-05-08 20:08:28 +00:00
Nate Begeman
d8624ed07f Proving once again that I am not as smart as the compiler
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28169 91177308-0d34-0410-b5e6-96231b3b80d8
2006-05-08 19:09:24 +00:00
Nate Begeman
4667f2cbad Fold more shifts into inserts, and update the README
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28168 91177308-0d34-0410-b5e6-96231b3b80d8
2006-05-08 17:38:32 +00:00
Nate Begeman
93376b083e Update some stuff now that the new rlwimi code has gone in
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28162 91177308-0d34-0410-b5e6-96231b3b80d8
2006-05-08 02:52:38 +00:00
Chris Lattner
55c63257f3 New note, Nate, please check to see if I'm full of it :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28118 91177308-0d34-0410-b5e6-96231b3b80d8
2006-05-05 05:36:15 +00:00
Chris Lattner
ed93790517 add a note, move an altivec todo to the altivec list.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27654 91177308-0d34-0410-b5e6-96231b3b80d8
2006-04-13 16:48:00 +00:00
Chris Lattner
220d2b89d6 add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27360 91177308-0d34-0410-b5e6-96231b3b80d8
2006-04-02 07:20:00 +00:00
Chris Lattner
b86bd2cee2 Split out altivec notes into their own README
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27168 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-27 07:04:16 +00:00
Chris Lattner
420736dc85 #include Intrinsics.h into all dag isels
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27109 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-25 06:47:10 +00:00
Chris Lattner
057f09bc0b add another note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27077 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-24 20:04:27 +00:00
Chris Lattner
716aefcd91 add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27000 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-23 21:28:44 +00:00
Chris Lattner
9d86a9dff2 This has been implemented. Tweak it into another note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26944 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-22 05:33:23 +00:00
Nate Begeman
c0a8b6df2a Update readme
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26924 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-21 18:58:20 +00:00
Chris Lattner
ef040dd4a3 minor note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26912 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-21 00:47:09 +00:00
Chris Lattner
28097d086f Add a note about the MUL -> FMADD vector bug.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26874 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-19 22:08:08 +00:00
Chris Lattner
28b1a0b532 notes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26856 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-19 05:33:30 +00:00
Nate Begeman
81e8097377 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26814 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-17 01:40:33 +00:00
Nate Begeman
1ad9b3a3cc Notes on how to kill the eeevil brtwoway, and make ppc branch selector
more target independant, generate better code, and be less conservative.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26809 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-16 22:37:48 +00:00
Chris Lattner
ed51169cd8 add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26807 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-16 22:25:55 +00:00
Nate Begeman
2df992883b Another case we could do better on.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26795 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-16 18:50:44 +00:00
Chris Lattner
49f398b96a add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26605 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-08 00:25:47 +00:00
Chris Lattner
5a63c47fb5 add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26585 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-07 04:42:59 +00:00
Chris Lattner
00d18f0879 add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26448 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-01 06:36:20 +00:00
Chris Lattner
5126984b1d 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26447 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-01 05:50:56 +00:00
Chris Lattner
8c13d0a573 Use a target-specific dag-combine to implement CodeGen/PowerPC/fp-int-fp.ll.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26445 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-01 04:57:39 +00:00
Chris Lattner
f4c8575c27 remove implemented item
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26418 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-28 06:36:04 +00:00
Nate Begeman
6e53ceb0d4 readme updates
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26405 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-27 22:08:36 +00:00
Chris Lattner
8d3f490991 Move emails from nate into public places
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26051 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-08 06:43:51 +00:00
Chris Lattner
213845367c add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25984 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-05 05:27:35 +00:00
Nate Begeman
a6973c348b Remove some stuff that now works
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25963 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-04 07:29:35 +00:00
Chris Lattner
1541bc3a23 add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25944 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-03 22:06:45 +00:00
Chris Lattner
33c1dab0bd remove some target-indep and implemented notes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25930 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-03 06:22:11 +00:00
Nate Begeman
a63fee898b Flesh out a couple of the items in the README
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25928 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-03 05:17:06 +00:00
Chris Lattner
d463f7f698 Add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25921 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-03 01:49:49 +00:00