* tree-vect-stmts.c (supportable_widening_operation): Expand
WIDEN_MULT_EXPR via VEC_WIDEN_MULT_EVEN/ODD_EXPR if possible.
---
gcc/ChangeLog | 3 ++
gcc/tree-vect-stmts.c | 96 +++++++++++++++++++++++++------------------------
2 files changed, 53 insertions(+), 46 deletions(-)
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 9caf1c6..fe6a997 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -6199,7 +6199,8 @@ vect_is_simple_use_1 (tree operand, gimple stmt,
loop_vec_info loop_vinfo,
bool
supportable_widening_operation (enum tree_code code, gimple stmt,
tree vectype_out, tree vectype_in,
- tree *decl1, tree *decl2,
+ tree *decl1 ATTRIBUTE_UNUSED,
+ tree *decl2 ATTRIBUTE_UNUSED,
enum tree_code *code1, enum tree_code *code2,
int *multi_step_cvt,
VEC (tree, heap) **interm_types)
@@ -6207,7 +6208,6 @@ supportable_widening_operation (enum tree_code code,
gimple stmt,
stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
loop_vec_info loop_info = STMT_VINFO_LOOP_VINFO (stmt_info);
struct loop *vect_loop = NULL;
- bool ordered_p;
enum machine_mode vec_mode;
enum insn_code icode1, icode2;
optab optab1, optab2;
@@ -6223,56 +6223,60 @@ supportable_widening_operation (enum tree_code code,
gimple stmt,
if (loop_info)
vect_loop = LOOP_VINFO_LOOP (loop_info);
- /* The result of a vectorized widening operation usually requires two vectors
- (because the widened results do not fit into one vector). The generated
- vector results would normally be expected to be generated in the same
- order as in the original scalar computation, i.e. if 8 results are
- generated in each vector iteration, they are to be organized as follows:
- vect1: [res1,res2,res3,res4], vect2: [res5,res6,res7,res8].
-
- However, in the special case that the result of the widening operation is
- used in a reduction computation only, the order doesn't matter (because
- when vectorizing a reduction we change the order of the computation).
- Some targets can take advantage of this and generate more efficient code.
- For example, targets like Altivec, that support widen_mult using a
sequence
- of {mult_even,mult_odd} generate the following vectors:
- vect1: [res1,res3,res5,res7], vect2: [res2,res4,res6,res8].
-
- When vectorizing outer-loops, we execute the inner-loop sequentially
- (each vectorized inner-loop iteration contributes to VF outer-loop
- iterations in parallel). We therefore don't allow to change the order
- of the computation in the inner-loop during outer-loop vectorization. */
-
- if (vect_loop
- && STMT_VINFO_RELEVANT (stmt_info) == vect_used_by_reduction
- && !nested_in_vect_loop_p (vect_loop, stmt))
- ordered_p = false;
- else
- ordered_p = true;
-
- if (!ordered_p
- && code == WIDEN_MULT_EXPR
- && targetm.vectorize.builtin_mul_widen_even
- && targetm.vectorize.builtin_mul_widen_even (vectype)
- && targetm.vectorize.builtin_mul_widen_odd
- && targetm.vectorize.builtin_mul_widen_odd (vectype))
- {
- if (vect_print_dump_info (REPORT_DETAILS))
- fprintf (vect_dump, "Unordered widening operation detected.");
-
- *code1 = *code2 = CALL_EXPR;
- *decl1 = targetm.vectorize.builtin_mul_widen_even (vectype);
- *decl2 = targetm.vectorize.builtin_mul_widen_odd (vectype);
- return true;
- }
-
switch (code)
{
case WIDEN_MULT_EXPR:
+ /* The result of a vectorized widening operation usually requires
+ two vectors (because the widened results do not fit into one vector).
+ The generated vector results would normally be expected to be
+ generated in the same order as in the original scalar computation,
+ i.e. if 8 results are generated in each vector iteration, they are
+ to be organized as follows:
+ vect1: [res1,res2,res3,res4],
+ vect2: [res5,res6,res7,res8].
+
+ However, in the special case that the result of the widening
+ operation is used in a reduction computation only, the order doesn't
+ matter (because when vectorizing a reduction we change the order of
+ the computation). Some targets can take advantage of this and
+ generate more efficient code. For example, targets like Altivec,
+ that support widen_mult using a sequence of {mult_even,mult_odd}
+ generate the following vectors:
+ vect1: [res1,res3,res5,res7],
+ vect2: [res2,res4,res6,res8].
+
+ When vectorizing outer-loops, we execute the inner-loop sequentially
+ (each vectorized inner-loop iteration contributes to VF outer-loop
+ iterations in parallel). We therefore don't allow to change the
+ order of the computation in the inner-loop during outer-loop
+ vectorization. */
+ /* TODO: Another case in which order doesn't *really* matter is when we
+ widen and then contract again, e.g. (short)((int)x * y >> 8).
+ Normally, pack_trunc performs an even/odd permute, whereas the
+ repack from an even/odd expansion would be an interleave, which
+ would be significantly simpler for e.g. AVX2. */
+ /* In any case, in order to avoid duplicating the code below, recurse
+ on VEC_WIDEN_MULT_EVEN_EXPR. If it succeeds, all the return values
+ are properly set up for the caller. If we fail, we'll continue with
+ a VEC_WIDEN_MULT_LO/HI_EXPR check. */
+ if (vect_loop
+ && STMT_VINFO_RELEVANT (stmt_info) == vect_used_by_reduction
+ && !nested_in_vect_loop_p (vect_loop, stmt)
+ && supportable_widening_operation (VEC_WIDEN_MULT_EVEN_EXPR,
+ stmt, vectype_out, vectype_in,
+ NULL, NULL, code1, code2,
+ multi_step_cvt, interm_types))
+ return true;
c1 = VEC_WIDEN_MULT_LO_EXPR;
c2 = VEC_WIDEN_MULT_HI_EXPR;
break;
+ case VEC_WIDEN_MULT_EVEN_EXPR:
+ /* Support the recursion induced just above. */
+ c1 = VEC_WIDEN_MULT_EVEN_EXPR;
+ c2 = VEC_WIDEN_MULT_ODD_EXPR;
+ break;
+
case WIDEN_LSHIFT_EXPR:
c1 = VEC_WIDEN_LSHIFT_LO_EXPR;
c2 = VEC_WIDEN_LSHIFT_HI_EXPR;
@@ -6298,7 +6302,7 @@ supportable_widening_operation (enum tree_code code,
gimple stmt,
gcc_unreachable ();
}
- if (BYTES_BIG_ENDIAN)
+ if (BYTES_BIG_ENDIAN && c1 != VEC_WIDEN_MULT_EVEN_EXPR)
{
enum tree_code ctmp = c1;
c1 = c2;
--
1.7.10.4
