From: Andrew Pinski <apin...@marvell.com>
This just adds a simplification to simplify_vector_constructor for
vector of 1 element to be VCE which should reduce memory usage in
the compiler and maybe allow for some more optimizations.
OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
PR tree-optimization/101540
gcc/ChangeLog:
* tree-ssa-forwprop.c (simplify_vector_constructor):
Simplify constructor of vector of 1 element to just
be a VIEW_CONVERT_EXPR.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/pr101540-1.c: New test.
---
gcc/testsuite/gcc.dg/tree-ssa/pr101540-1.c | 13 +++++++++++++
gcc/tree-ssa-forwprop.c | 13 +++++++++++++
2 files changed, 26 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr101540-1.c
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr101540-1.c
b/gcc/testsuite/gcc.dg/tree-ssa/pr101540-1.c
new file mode 100644
index 00000000000..73fb342e029
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr101540-1.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-forwprop1" } */
+/* PR tree-optimization/101540 */
+typedef unsigned char __attribute__((__vector_size__ (1))) W;
+
+W foo (unsigned char uc)
+{
+ return (W){uc};
+}
+/* The constructor in the above function should be converted into a VCE. */
+/* { dg-final { scan-tree-dump-times "VIEW_CONVERT_EXPR" 1 "forwprop1"} } */
+// {uc_1(D)}
+/* { dg-final { scan-tree-dump-times "{uc_\[0-9\]+.D.}" 0 "forwprop1"} } */
diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
index a830bab78ba..94b92d3d0af 100644
--- a/gcc/tree-ssa-forwprop.c
+++ b/gcc/tree-ssa-forwprop.c
@@ -2392,6 +2392,19 @@ simplify_vector_constructor (gimple_stmt_iterator *gsi)
elem_type = TREE_TYPE (type);
elem_size = TREE_INT_CST_LOW (TYPE_SIZE (elem_type));
+ /* Special case V1 constructor with the same type to being a VCE. */
+ if (nelts == 1 && CONSTRUCTOR_NELTS (op) == 1)
+ {
+ tree op1 = CONSTRUCTOR_ELT (op, 0)->value;
+ if (useless_type_conversion_p (elem_type, TREE_TYPE (op1)))
+ {
+ op1 = build1 (VIEW_CONVERT_EXPR, type, op1);
+ gimple_assign_set_rhs_from_tree (gsi, op1);
+ update_stmt (gsi_stmt (*gsi));
+ return true;
+ }
+ }
+
orig[0] = NULL;
orig[1] = NULL;
conv_code = ERROR_MARK;
--
2.17.1
