On 8/22/24 12:46, Patrick O'Neill wrote:
These cases are handled in the expander
(riscv-v.cc:expand_const_vector). We need the vector builder to detect
these cases so extract that out into a new riscv-v.h header file.
gcc/ChangeLog:
* config/riscv/riscv-v.cc (class rvv_builder): Move to riscv-v.h.
* config/riscv/riscv.cc (riscv_const_insns): Emit placeholder costs for
bool/stepped const vectors.
* config/riscv/riscv-v.h: New file.
Signed-off-by: Patrick O'Neill <patr...@rivosinc.com>
---
<snip>
diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index eb1c172d1ce..a820cadd205 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -75,6 +75,7 @@ along with GCC; see the file COPYING3. If not see
#include "gcse.h"
#include "tree-dfa.h"
#include "target-globals.h"
+#include "riscv-v.h"
/* This file should be included last. */
#include "target-def.h"
@@ -2145,6 +2146,10 @@ riscv_const_insns (rtx x, bool allow_new_pseudos)
rtx elt;
if (const_vec_duplicate_p (x, &elt))
{
+ if (GET_MODE_CLASS (GET_MODE (x)) == MODE_VECTOR_BOOL)
+ /* Duplicate values of 0/1 can be emitted using vmv.v.i. */
+ return 1;
+
/* We don't allow CONST_VECTOR for DI vector on RV32
system since the ELT constant value can not held
within a single register to disable reload a DI
@@ -2184,6 +2189,43 @@ riscv_const_insns (rtx x, bool allow_new_pseudos)
accurately according to BASE && STEP. */
return 1;
}
+
+ if (CONST_VECTOR_STEPPED_P (x))
+ {
+ /* Some cases are unhandled so we need construct a builder to
+ detect/allow those cases to be handled by the fallthrough
+ handler. */
+ unsigned int nelts_per_pattern = CONST_VECTOR_NELTS_PER_PATTERN
(x);
+ unsigned int npatterns = CONST_VECTOR_NPATTERNS (x);
+ rvv_builder builder (mode, npatterns, nelts_per_pattern);
+ for (unsigned int i = 0; i < nelts_per_pattern; i++)
+ {
+ for (unsigned int j = 0; j < npatterns; j++)
+ builder.quick_push (CONST_VECTOR_ELT (x, i * npatterns +
j));
+ }
+ builder.finalize ();
+
+ if (builder.single_step_npatterns_p ())
+ {
+ if (builder.npatterns_all_equal_p ())
+ {
+ /* TODO: This cost is not accurate. */
+ return 1;
+ }
+ else
+ {
+ /* TODO: This cost is not accurate. */
+ return 1;
+ }
+ }
+ else if (builder.interleaved_stepped_npatterns_p ())
+ {
+ /* TODO: This cost is not accurate. */
+ return 1;
+ }
+
+ /* Fallthrough to catch all pattern. */
Precommit highlighted that patches 6-8 fail to build.
This comment should instead be a return 0; since the catch all pattern
isn't added till patch 9.
Patch 9 should then replace the return 0; with this comment.
I'll fix this before landing or in v2.
Patrick
+ }
}
/* TODO: We may support more const vector in the future. */
