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riscv-gcc-1
Commit ad25ba17 by Richard Kenner
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(simplify_comparison): Can remove NOT on both operands if we swap 

comparison code.

From-SVN: r6410
parent 2f607b94
Showing with 8 additions and 7 deletions
gcc/combine.c
......@@ -8429,7 +8429,7 @@ simplify_comparison (code, pop0, pop1)
&& GET_CODE (XEXP (XEXP (op0, 0), 0)) == SUBREG
&& GET_CODE (XEXP (XEXP (op1, 0), 0)) == SUBREG
&& (GET_MODE (SUBREG_REG (XEXP (XEXP (op0, 0), 0)))
== GET_MODE (SUBREG_REG (XEXP (XEXP (op0, 0), 0))))
== GET_MODE (SUBREG_REG (XEXP (XEXP (op1, 0), 0))))
&& GET_CODE (XEXP (op0, 1)) == CONST_INT
&& GET_CODE (XEXP (op1, 1)) == CONST_INT
&& GET_CODE (XEXP (XEXP (op0, 0), 1)) == CONST_INT
......@@ -8517,12 +8517,13 @@ simplify_comparison (code, pop0, pop1)
code = unsigned_condition (code);
}
/* If both operands are NOT or both are NEG, we can strip off the
outer operation if this is just an equality comparison. */
else if ((code == EQ || code == NE)
&& ((GET_CODE (op0) == NOT && GET_CODE (op1) == NOT)
|| (GET_CODE (op0) == NEG && GET_CODE (op1) == NEG)))
op0 = XEXP (op0, 0), op1 = XEXP (op1, 0);
/* If both operands are NOT, we can strip off the outer operation
and adjust the comparison code for swapped operands; similarly for
NEG, except that this must be an equality comparison. */
else if ((GET_CODE (op0) == NOT && GET_CODE (op1) == NOT)
|| (GET_CODE (op0) == NEG && GET_CODE (op1) == NEG
&& (code == EQ || code == NE)))
op0 = XEXP (op0, 0), op1 = XEXP (op1, 0), code = swap_condition (code);
else
break;
......
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