Optimize a couple of common patterns involving conditional moves where the false

value is zero. Instead of a cmov + op, issue an conditional op instead. e.g.
    cmp   r9, r4
    mov   r4, #0
    moveq r4, #1 
    orr   lr, lr, r4

should be:
    cmp   r9, r4
    orreq lr, lr, #1

That is, optimize (or x, (cmov 0, y, cond)) to (or.cond x, y). Similarly extend
this to xor as well as (and x, (cmov -1, y, cond)) => (and.cond x, y).

It's possible to extend this to ADD and SUB but I don't think they are common.

rdar://8659097

llvm-svn: 151224

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/Target/ARM/ARMISelLowering.h b/llvm/lib/Target/ARM/ARMISelLowering.h
index 527156aac41..a72a476e962 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.h
+++ b/llvm/lib/Target/ARM/ARMISelLowering.h
@@ -56,7 +56,11 @@ namespace llvm {
       CMPFP,        // ARM VFP compare instruction, sets FPSCR.
       CMPFPw0,      // ARM VFP compare against zero instruction, sets FPSCR.
       FMSTAT,       // ARM fmstat instruction.
+
       CMOV,         // ARM conditional move instructions.
+      CAND,         // ARM conditional and instructions.
+      COR,          // ARM conditional or instructions.
+      CXOR,         // ARM conditional xor instructions.
 
       BCC_i64,