This patch was part of the original patch we acquired from Honza and Martin.
It simplifies vector elements that are inactive, according to the mask.
2018-09-05 Jan Hubicka <j...@suse.cz>
Martin Jambor <mjam...@suse.cz>
* simplify-rtx.c (simplify_merge_mask): New function.
(simplify_ternary_operation): Use it, also see if VEC_MERGEs with the
same masks are used in op1 or op2.
---
gcc/simplify-rtx.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 81 insertions(+)
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 89487f2..6f27bda 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -5578,6 +5578,65 @@ simplify_cond_clz_ctz (rtx x, rtx_code cmp_code, rtx true_val, rtx false_val)
return NULL_RTX;
}
+/* X is an operand number OP of VEC_MERGE operation with MASK.
+ Try to simplify using knowledge that values outside of MASK
+ will not be used. */
+
+rtx
+simplify_merge_mask (rtx x, rtx mask, int op)
+{
+ gcc_assert (VECTOR_MODE_P (GET_MODE (x)));
+ poly_uint64 nunits = GET_MODE_NUNITS (GET_MODE (x));
+ if (GET_CODE (x) == VEC_MERGE && rtx_equal_p (XEXP (x, 2), mask))
+ {
+ if (!side_effects_p (XEXP (x, 1 - op)))
+ return XEXP (x, op);
+ }
+ if (side_effects_p (x))
+ return NULL_RTX;
+ if (UNARY_P (x)
+ && VECTOR_MODE_P (GET_MODE (XEXP (x, 0)))
+ && maybe_eq (GET_MODE_NUNITS (GET_MODE (XEXP (x, 0))), nunits))
+ {
+ rtx top0 = simplify_merge_mask (XEXP (x, 0), mask, op);
+ if (top0)
+ return simplify_gen_unary (GET_CODE (x), GET_MODE (x), top0,
+ GET_MODE (XEXP (x, 0)));
+ }
+ if (BINARY_P (x)
+ && VECTOR_MODE_P (GET_MODE (XEXP (x, 0)))
+ && maybe_eq (GET_MODE_NUNITS (GET_MODE (XEXP (x, 0))), nunits)
+ && VECTOR_MODE_P (GET_MODE (XEXP (x, 1)))
+ && maybe_eq (GET_MODE_NUNITS (GET_MODE (XEXP (x, 1))), nunits))
+ {
+ rtx top0 = simplify_merge_mask (XEXP (x, 0), mask, op);
+ rtx top1 = simplify_merge_mask (XEXP (x, 1), mask, op);
+ if (top0 || top1)
+ return simplify_gen_binary (GET_CODE (x), GET_MODE (x),
+ top0 ? top0 : XEXP (x, 0),
+ top1 ? top1 : XEXP (x, 1));
+ }
+ if (GET_RTX_CLASS (GET_CODE (x)) == RTX_TERNARY
+ && VECTOR_MODE_P (GET_MODE (XEXP (x, 0)))
+ && maybe_eq (GET_MODE_NUNITS (GET_MODE (XEXP (x, 0))), nunits)
+ && VECTOR_MODE_P (GET_MODE (XEXP (x, 1)))
+ && maybe_eq (GET_MODE_NUNITS (GET_MODE (XEXP (x, 1))), nunits)
+ && VECTOR_MODE_P (GET_MODE (XEXP (x, 2)))
+ && maybe_eq (GET_MODE_NUNITS (GET_MODE (XEXP (x, 2))), nunits))
+ {
+ rtx top0 = simplify_merge_mask (XEXP (x, 0), mask, op);
+ rtx top1 = simplify_merge_mask (XEXP (x, 1), mask, op);
+ rtx top2 = simplify_merge_mask (XEXP (x, 2), mask, op);
+ if (top0 || top1)
+ return simplify_gen_ternary (GET_CODE (x), GET_MODE (x),
+ GET_MODE (XEXP (x, 0)),
+ top0 ? top0 : XEXP (x, 0),
+ top1 ? top1 : XEXP (x, 1),
+ top2 ? top2 : XEXP (x, 2));
+ }
+ return NULL_RTX;
+}
+
/* Simplify CODE, an operation with result mode MODE and three operands,
OP0, OP1, and OP2. OP0_MODE was the mode of OP0 before it became
@@ -5967,6 +6026,28 @@ simplify_ternary_operation (enum rtx_code code, machine_mode mode,
&& !side_effects_p (op2) && !side_effects_p (op1))
return op0;
+ if (!side_effects_p (op2))
+ {
+ rtx top0 = simplify_merge_mask (op0, op2, 0);
+ rtx top1 = simplify_merge_mask (op1, op2, 1);
+ if (top0 || top1)
+ return simplify_gen_ternary (code, mode, mode,
+ top0 ? top0 : op0,
+ top1 ? top1 : op1, op2);
+ }
+
+ if (GET_CODE (op0) == VEC_MERGE
+ && rtx_equal_p (op2, XEXP (op0, 2))
+ && !side_effects_p (XEXP (op0, 1)) && !side_effects_p (op2))
+ return simplify_gen_ternary (code, mode, mode,
+ XEXP (op0, 0), op1, op2);
+
+ if (GET_CODE (op1) == VEC_MERGE
+ && rtx_equal_p (op2, XEXP (op1, 2))
+ && !side_effects_p (XEXP (op0, 0)) && !side_effects_p (op2))
+ return simplify_gen_ternary (code, mode, mode,
+ XEXP (op0, 1), op1, op2);
+
break;
default:
