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authorNate Begeman <natebegeman@mac.com>2006-05-08 02:52:38 +0000
committerNate Begeman <natebegeman@mac.com>2006-05-08 02:52:38 +0000
commit93376b083e11f6dfcc678fe68abbc801eaa0a348 (patch)
tree32506856931979fa7651ac6d481839cc1e2862e2 /lib/Target/PowerPC/README.txt
parent5c742681edc9d0e8be16f7518af5429d2b643078 (diff)
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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
Diffstat (limited to 'lib/Target/PowerPC/README.txt')
-rw-r--r--lib/Target/PowerPC/README.txt69
1 files changed, 0 insertions, 69 deletions
diff --git a/lib/Target/PowerPC/README.txt b/lib/Target/PowerPC/README.txt
index bbe311cb38..68fa8f2ae6 100644
--- a/lib/Target/PowerPC/README.txt
+++ b/lib/Target/PowerPC/README.txt
@@ -85,75 +85,6 @@ more than one use. Itanium will want this too.
===-------------------------------------------------------------------------===
-#define ARRAY_LENGTH 16
-
-union bitfield {
- struct {
-#ifndef __ppc__
- unsigned int field0 : 6;
- unsigned int field1 : 6;
- unsigned int field2 : 6;
- unsigned int field3 : 6;
- unsigned int field4 : 3;
- unsigned int field5 : 4;
- unsigned int field6 : 1;
-#else
- unsigned int field6 : 1;
- unsigned int field5 : 4;
- unsigned int field4 : 3;
- unsigned int field3 : 6;
- unsigned int field2 : 6;
- unsigned int field1 : 6;
- unsigned int field0 : 6;
-#endif
- } bitfields, bits;
- unsigned int u32All;
- signed int i32All;
- float f32All;
-};
-
-
-typedef struct program_t {
- union bitfield array[ARRAY_LENGTH];
- int size;
- int loaded;
-} program;
-
-
-void AdjustBitfields(program* prog, unsigned int fmt1)
-{
- prog->array[0].bitfields.field0 = fmt1;
- prog->array[0].bitfields.field1 = fmt1 + 1;
-}
-
-We currently generate:
-
-_AdjustBitfields:
- lwz r2, 0(r3)
- addi r5, r4, 1
- rlwinm r2, r2, 0, 0, 19
- rlwinm r5, r5, 6, 20, 25
- rlwimi r2, r4, 0, 26, 31
- or r2, r2, r5
- stw r2, 0(r3)
- blr
-
-We should teach someone that or (rlwimi, rlwinm) with disjoint masks can be
-turned into rlwimi (rlwimi)
-
-The better codegen would be:
-
-_AdjustBitfields:
- lwz r0,0(r3)
- rlwinm r4,r4,0,0xff
- rlwimi r0,r4,0,26,31
- addi r4,r4,1
- rlwimi r0,r4,6,20,25
- stw r0,0(r3)
- blr
-
-===-------------------------------------------------------------------------===
-
Compile this:
int %f1(int %a, int %b) {