diff options
Diffstat (limited to 'gcc/combine.c')
-rw-r--r-- | gcc/combine.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index b8ac09b..a498b58 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -10811,6 +10811,21 @@ simplify_comparison (code, pop0, pop1) continue; } + /* Convert (ne (and (lshiftrt (not X)) 1) 0) to + (eq (and (lshiftrt X) 1) 0). */ + if (const_op == 0 && equality_comparison_p + && XEXP (op0, 1) == const1_rtx + && GET_CODE (XEXP (op0, 0)) == LSHIFTRT + && GET_CODE (XEXP (XEXP (op0, 0), 0)) == NOT) + { + op0 = simplify_and_const_int + (op0, mode, gen_rtx_combine (LSHIFTRT, mode, + XEXP (XEXP (XEXP (op0, 0), 0), 0), + XEXP (XEXP (op0, 0), 1)), + (HOST_WIDE_INT) 1); + code = (code == NE ? EQ : NE); + continue; + } break; case ASHIFT: |