https://gcc.gnu.org/g:f815c8f308c29271702255ec5690b77896ce71f3
commit f815c8f308c29271702255ec5690b77896ce71f3
Author: Patrick O'Neill <patr...@rivosinc.com>
Date: Tue Aug 20 12:01:22 2024 -0700
RISC-V: Handle 0.0 floating point pattern costing to match const_vector
expander
The comment previously here stated that the Wc0/Wc1 cases are handled by
the vi constraint but that is not true for the 0.0 Wc0 case.
gcc/ChangeLog:
* config/riscv/riscv-v.h (valid_vec_immediate_p): Add new helper.
* config/riscv/riscv-v.cc (valid_vec_immediate_p): Ditto.
(expand_const_vector): Use new helper.
* config/riscv/riscv.cc (riscv_const_insns): Handle 0.0
floating-point
case.
Signed-off-by: Patrick O'Neill <patr...@rivosinc.com>
(cherry picked from commit 282bbc9381c563c746a43bf35e93d349188cc8e8)
Diff:
---
gcc/config/riscv/riscv-v.cc | 11 ++++++++++-
gcc/config/riscv/riscv-v.h | 2 ++
gcc/config/riscv/riscv.cc | 8 +++-----
3 files changed, 15 insertions(+), 6 deletions(-)
diff --git a/gcc/config/riscv/riscv-v.cc b/gcc/config/riscv/riscv-v.cc
index 76ef3f643643..8aaeaea29911 100644
--- a/gcc/config/riscv/riscv-v.cc
+++ b/gcc/config/riscv/riscv-v.cc
@@ -794,6 +794,15 @@ const_vec_all_in_range_p (rtx vec, poly_int64 minval,
poly_int64 maxval)
return true;
}
+/* Returns true if the vector's elements are all duplicates in
+ range -16 ~ 15 integer or 0.0 floating-point. */
+
+bool
+valid_vec_immediate_p (rtx x)
+{
+ return (satisfies_constraint_vi (x) || satisfies_constraint_Wc0 (x));
+}
+
/* Return a const vector of VAL. The VAL can be either const_int or
const_poly_int. */
@@ -1185,7 +1194,7 @@ expand_const_vector (rtx target, rtx src)
{
/* Element in range -16 ~ 15 integer or 0.0 floating-point,
we use vmv.v.i instruction. */
- if (satisfies_constraint_vi (src) || satisfies_constraint_Wc0 (src))
+ if (valid_vec_immediate_p (src))
{
rtx ops[] = {result, src};
emit_vlmax_insn (code_for_pred_mov (mode), UNARY_OP, ops);
diff --git a/gcc/config/riscv/riscv-v.h b/gcc/config/riscv/riscv-v.h
index 4635b5415c78..e7b095f094e6 100644
--- a/gcc/config/riscv/riscv-v.h
+++ b/gcc/config/riscv/riscv-v.h
@@ -83,6 +83,8 @@ private:
unsigned int m_inner_bytes_size;
};
+extern bool valid_vec_immediate_p(rtx);
+
} // namespace riscv_vector
#endif // GCC_RISCV_V_H
diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index efa5d1853438..335ca5e6c89b 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -2158,11 +2158,9 @@ riscv_const_insns (rtx x, bool allow_new_pseudos)
if (maybe_gt (GET_MODE_SIZE (smode), UNITS_PER_WORD)
&& !immediate_operand (elt, Pmode))
return 0;
- /* Constants from -16 to 15 can be loaded with vmv.v.i.
- The Wc0, Wc1 constraints are already covered by the
- vi constraint so we do not need to check them here
- separately. */
- if (satisfies_constraint_vi (x))
+ /* Constants in range -16 ~ 15 integer or 0.0 floating-point
+ can be emitted using vmv.v.i. */
+ if (valid_vec_immediate_p (x))
return 1;
/* Any int/FP constants can always be broadcast from a
