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      1 ; RUN: llc < %s -O1 -mtriple=i386-apple-darwin -x86-asm-syntax=intel | FileCheck %s
      2 ;
      3 ; Interesting test case where %tmp1220 = xor i32 %tmp862, %tmp592 and
      4 ; %tmp1676 = xor i32 %tmp1634, %tmp1530 have zero demanded bits after
      5 ; DAGCombiner optimization pass.  These are changed to undef and in turn
      6 ; the successor shl(s) become shl undef, 1.  This pattern then matches
      7 ; shl x, 1 -> add x, x.  add undef, undef doesn't guarantee the low
      8 ; order bit is zero and is incorrect.
      9 ;
     10 ; See rdar://9453156 and rdar://9487392.
     11 ;
     12 
     13 ; Use intel syntax, or "shl" might hit "pushl".
     14 
     15 ; CHECK-NOT: shl
     16 define i32 @foo(i8* %a0, i32* %a2) nounwind {
     17 entry:
     18   %tmp0 = alloca i8
     19   %tmp1 = alloca i32
     20   store i8 1, i8* %tmp0
     21   %tmp921.i7845 = load i8, i8* %a0, align 1
     22   %tmp309 = xor i8 %tmp921.i7845, 104
     23   %tmp592 = zext i8 %tmp309 to i32
     24   %tmp862 = xor i32 1293461297, %tmp592
     25   %tmp1220 = xor i32 %tmp862, %tmp592
     26   %tmp1506 = shl i32 %tmp1220, 1
     27   %tmp1530 = sub i32 %tmp592, %tmp1506
     28   %tmp1557 = sub i32 %tmp1530, 542767629
     29   %tmp1607 = and i32 %tmp1557, 1
     30   store i32 %tmp1607, i32* %tmp1
     31   %tmp1634 = and i32 %tmp1607, 2080309246
     32   %tmp1676 = xor i32 %tmp1634, %tmp1530
     33   %tmp1618 = shl i32 %tmp1676, 1
     34   %tmp1645 = sub i32 %tmp862, %tmp1618
     35   %tmp1697 = and i32 %tmp1645, 1
     36   store i32 %tmp1697, i32* %a2
     37   ret i32 %tmp1607
     38 }
     39 
     40 ; CHECK-NOT: shl
     41 ; shl undef, 0 -> undef
     42 define i32 @foo2_undef() nounwind {
     43 entry:
     44   %tmp2 = shl i32 undef, 0;
     45   ret i32 %tmp2
     46 }
     47 
     48 ; CHECK-NOT: shl
     49 ; shl undef, x -> 0
     50 define i32 @foo1_undef(i32* %a0) nounwind {
     51 entry:
     52   %tmp1 = load i32, i32* %a0, align 1
     53   %tmp2 = shl i32 undef, %tmp1;
     54   ret i32 %tmp2
     55 }
     56