[llvm-commits] [llvm] r117876 - /llvm/trunk/lib/CodeGen/PeepholeOptimizer.cpp

[Bill Wendling]

Author: void
Date: Sun Oct 31 17:07:12 2010
New Revision: 117876

URL: http://llvm.org/viewvc/llvm-project?rev=117876&view=rev
Log:
Disable the peephole optimizer until 186.crafty on armv6 is fixed. This is what
looks like is happening:

Without the peephole optimizer:
  (1)   sub     r6, r6, #32
        orr     r12, r12, lr, lsl r9
        orr     r2, r2, r3, lsl r10
  (x)   cmp     r6, #0
        ldr     r9, LCPI2_10
        ldr     r10, LCPI2_11
  (2)   sub     r8, r8, #32
  (a)   movge   r12, lr, lsr r6
  (y)   cmp     r8, #0
LPC2_10:
        ldr     lr, [pc, r10]
  (b)   movge   r2, r3, lsr r8

With the peephole optimizer:
        ldr     r9, LCPI2_10
        ldr     r10, LCPI2_11
  (1*)  subs    r6, r6, #32
  (2*)  subs    r8, r8, #32
  (a*)  movge   r12, lr, lsr r6
  (b*)  movge   r2, r3, lsr r8

(1) is used by (x) for the conditional move at (a). (2) is used by (y) for the
conditional move at (b). After the peephole optimizer, these the flags resulting
from (1*) are ignored and only the flags from (2*) are considered for both
conditional moves.

Modified:
    llvm/trunk/lib/CodeGen/PeepholeOptimizer.cpp

Modified: llvm/trunk/lib/CodeGen/PeepholeOptimizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PeepholeOptimizer.cpp?rev=117876&r1=117875&r2=117876&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/PeepholeOptimizer.cpp (original)
+++ llvm/trunk/lib/CodeGen/PeepholeOptimizer.cpp Sun Oct 31 17:07:12 2010
@@ -276,9 +276,11 @@
 
       if (MI->getDesc().isCompare() &&
           !MI->getDesc().hasUnmodeledSideEffects()) {
+#if 0
         if (OptimizeCmpInstr(MI, MBB, MII))
           Changed = true;
         else
+#endif
           ++MII;
       } else {
         Changed |= OptimizeExtInstr(MI, MBB, LocalMIs);