This introduces simplify_logical_relational_operation. Currently the
only thing implemented it can simplify is the IOR of two CONDs of the
same arguments.
Tested on powerpc64-linux {-m32,-m64}.
Is this okay for trunk?
Segher
2018-11-06 Segher Boessenkool <seg...@kernel.crashing.org>
* simplify-rtx.c (comparison_to_mask): New function.
(mask_to_comparison): New function.
(simplify_logical_relational_operation): New function.
(simplify_binary_operation_1): Call
simplify_logical_relational_operation.
---
gcc/simplify-rtx.c | 130 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 130 insertions(+)
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 9a70720..b2ba922 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -2125,6 +2125,132 @@ simplify_associative_operation (enum rtx_code code,
machine_mode mode,
return 0;
}
+/* Return a mask describing the COMPARISON. */
+static int
+comparison_to_mask (enum rtx_code comparison)
+{
+ switch (comparison)
+ {
+ case LT:
+ return 8;
+ case GT:
+ return 4;
+ case EQ:
+ return 2;
+ case UNORDERED:
+ return 1;
+
+ case LTGT:
+ return 12;
+ case LE:
+ return 10;
+ case GE:
+ return 6;
+ case UNLT:
+ return 9;
+ case UNGT:
+ return 5;
+ case UNEQ:
+ return 3;
+
+ case ORDERED:
+ return 14;
+ case NE:
+ return 13;
+ case UNLE:
+ return 11;
+ case UNGE:
+ return 7;
+
+ default:
+ gcc_unreachable ();
+ }
+}
+
+/* Return a comparison corresponding to the MASK. */
+static enum rtx_code
+mask_to_comparison (int mask)
+{
+ switch (mask)
+ {
+ case 8:
+ return LT;
+ case 4:
+ return GT;
+ case 2:
+ return EQ;
+ case 1:
+ return UNORDERED;
+
+ case 12:
+ return LTGT;
+ case 10:
+ return LE;
+ case 6:
+ return GE;
+ case 9:
+ return UNLT;
+ case 5:
+ return UNGT;
+ case 3:
+ return UNEQ;
+
+ case 14:
+ return ORDERED;
+ case 13:
+ return NE;
+ case 11:
+ return UNLE;
+ case 7:
+ return UNGE;
+
+ default:
+ gcc_unreachable ();
+ }
+}
+
+/* Simplify a logical operation CODE with result mode MODE, operating on OP0
+ and OP1, which should be both relational operations. Return 0 if no such
+ simplification is possible. */
+rtx
+simplify_logical_relational_operation (enum rtx_code code, machine_mode mode,
+ rtx op0, rtx op1)
+{
+ /* We only handle IOR of two relational operations. */
+ if (code != IOR)
+ return 0;
+
+ if (!(COMPARISON_P (op0) && COMPARISON_P (op1)))
+ return 0;
+
+ if (!(rtx_equal_p (XEXP (op0, 0), XEXP (op1, 0))
+ && rtx_equal_p (XEXP (op0, 1), XEXP (op1, 1))))
+ return 0;
+
+ enum rtx_code code0 = GET_CODE (op0);
+ enum rtx_code code1 = GET_CODE (op1);
+
+ /* We don't handle unsigned comparisons currently. */
+ if (code0 == LTU || code0 == GTU || code0 == LEU || code0 == GEU)
+ return 0;
+ if (code1 == LTU || code1 == GTU || code1 == LEU || code1 == GEU)
+ return 0;
+
+ int mask0 = comparison_to_mask (code0);
+ int mask1 = comparison_to_mask (code1);
+
+ int mask = mask0 | mask1;
+
+ if (mask == 15)
+ return const_true_rtx;
+
+ code = mask_to_comparison (mask);
+
+ op0 = XEXP (op1, 0);
+ op1 = XEXP (op1, 1);
+
+ return simplify_gen_relational (code, mode, VOIDmode, op0, op1);
+}
/* Simplify a binary operation CODE with result mode MODE, operating on OP0
and OP1. Return 0 if no simplification is possible.
@@ -2888,6 +3014,10 @@ simplify_binary_operation_1 (enum rtx_code code,
machine_mode mode,
tem = simplify_associative_operation (code, mode, op0, op1);
if (tem)
return tem;
+
+ tem = simplify_logical_relational_operation (code, mode, op0, op1);
+ if (tem)
+ return tem;
break;
case XOR:
--
1.8.3.1
