Hi,
I observed a vect-construct forwprop opportunity in x264 that we
could handle when checking for a nop conversion instead of a useless
conversion. IMHO a nop-conversion check is sufficient as we're only
dealing with permutations in simplify_vector_constructor.
This patch replaces uses of useless_type_conversion_p with
tree_nop_conversion_p in simplify_vector_constructor.
It was bootstrapped and regtested on x86 and power10, regtested on
riscv64, aarch64 still running.
There is a single scan-test failure on power
(gcc.target/powerpc/builtins-1.c) but it doesn't look
like a dealbreaker. I have yet to check it in more detail, though.
Regards
Robin
gcc/ChangeLog:
* tree-ssa-forwprop.cc (simplify_vector_constructor):
Allow nop conversions.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/rvv/autovec/pr118019-3.c: New test.
---
.../gcc.target/riscv/rvv/autovec/pr118019-3.c | 51 +++++++++++++++++++
gcc/tree-ssa-forwprop.cc | 16 +++---
2 files changed, 59 insertions(+), 8 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/autovec/pr118019-3.c
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr118019-3.c
b/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr118019-3.c
new file mode 100644
index 00000000000..6cb761f63c0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr118019-3.c
@@ -0,0 +1,51 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=rv64gcv_zvl512b -mabi=lp64d
-mno-vector-strict-align -mmax-vectorization -fdump-tree-optimized" } */
+
+/* Ensure we don't use a vector constructor but a permute. */
+
+typedef unsigned char uint8_t;
+typedef unsigned short uint16_t;
+typedef unsigned int uint32_t;
+
+#define HADAMARD4(d0, d1, d2, d3, s0, s1, s2, s3) {\
+ int t0 = s0 + s1;\
+ int t1 = s0 - s1;\
+ int t2 = s2 + s3;\
+ int t3 = s2 - s3;\
+ d0 = t0 + t2;\
+ d2 = t0 - t2;\
+ d1 = t1 + t3;\
+ d3 = t1 - t3;\
+}
+
+uint32_t
+abs2 (uint32_t a)
+{
+ uint32_t s = ((a >> 15) & 0x10001) * 0xffff;
+ return (a + s) ^ s;
+}
+
+int
+x264_pixel_satd_8x4 (uint8_t *pix1, int i_pix1, uint8_t *pix2, int i_pix2)
+{
+ uint32_t tmp[4][4];
+ uint32_t a0, a1, a2, a3;
+ int sum = 0;
+ for (int i = 0; i < 4; i++, pix1 += i_pix1, pix2 += i_pix2)
+ {
+ a0 = (pix1[0] - pix2[0]) + ((pix1[4] - pix2[4]) << 16);
+ a1 = (pix1[1] - pix2[1]) + ((pix1[5] - pix2[5]) << 16);
+ a2 = (pix1[2] - pix2[2]) + ((pix1[6] - pix2[6]) << 16);
+ a3 = (pix1[3] - pix2[3]) + ((pix1[7] - pix2[7]) << 16);
+ HADAMARD4 (tmp[i][0], tmp[i][1], tmp[i][2], tmp[i][3], a0, a1, a2, a3);
+ }
+#pragma GCC unroll 4
+ for (int i = 0; i < 4; i++)
+ {
+ HADAMARD4 (a0, a1, a2, a3, tmp[0][i], tmp[1][i], tmp[2][i], tmp[3][i]);
+ sum += abs2 (a0) + abs2 (a1) + abs2 (a2) + abs2 (a3);
+ }
+ return (((uint16_t) sum) + ((uint32_t) sum >> 16)) >> 1;
+}
+
+/* { dg-final { scan-tree-dump-not "BIT_FIELD_REF" "optimized" } } */
diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index 9f8d4ad3b44..5dbcdd7b4bd 100644
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -3827,11 +3827,11 @@ simplify_vector_constructor (gimple_stmt_iterator *gsi)
if (op1
&& TREE_CODE ((ref = TREE_OPERAND (op1, 0))) == SSA_NAME
&& VECTOR_TYPE_P (TREE_TYPE (ref))
- && (useless_type_conversion_p (TREE_TYPE (op1),
- TREE_TYPE (TREE_TYPE (ref)))
+ && (tree_nop_conversion_p (TREE_TYPE (op1),
+ TREE_TYPE (TREE_TYPE (ref)))
|| (VECTOR_TYPE_P (TREE_TYPE (op1))
- && useless_type_conversion_p (TREE_TYPE (TREE_TYPE (op1)),
- TREE_TYPE (TREE_TYPE (ref)))
+ && tree_nop_conversion_p (TREE_TYPE (TREE_TYPE (op1)),
+ TREE_TYPE (TREE_TYPE (ref)))
&& TYPE_VECTOR_SUBPARTS (TREE_TYPE (op1))
.is_constant (&nsubelts)))
&& constant_multiple_p (bit_field_size (op1), nsubelts,
@@ -4055,8 +4055,8 @@ simplify_vector_constructor (gimple_stmt_iterator *gsi)
{
gcc_assert (known_eq (TYPE_VECTOR_SUBPARTS (type),
TYPE_VECTOR_SUBPARTS (src_type))
- && useless_type_conversion_p (TREE_TYPE (type),
- TREE_TYPE (src_type)));
+ && tree_nop_conversion_p (TREE_TYPE (type),
+ TREE_TYPE (src_type)));
tree rhs = build1 (VIEW_CONVERT_EXPR, type, orig[0]);
orig[0] = make_ssa_name (type);
gassign *assign = gimple_build_assign (orig[0], rhs);
@@ -4192,8 +4192,8 @@ simplify_vector_constructor (gimple_stmt_iterator *gsi)
{
gcc_assert (known_eq (TYPE_VECTOR_SUBPARTS (type),
TYPE_VECTOR_SUBPARTS (perm_type))
- && useless_type_conversion_p (TREE_TYPE (type),
- TREE_TYPE (perm_type)));
+ && tree_nop_conversion_p (TREE_TYPE (type),
+ TREE_TYPE (perm_type)));
res = gimple_build (&stmts, VIEW_CONVERT_EXPR, type, res);
}
/* Blend in the actual constant. */
--
2.51.0
