https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112623
--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
But the problem is of course that you then can't have both at the same time,
vec_pack_trunk_v4sf from V8HF and V8BF unless we'd support "VOIDmode" there.
Note there's the "better" {s,z}ext optabs which have two modes and could
support V8HF to V8SF conversions, but it doesn't work to model the
pack/unpack style of ISA with this.
The ambiguities would support using a conversion optab for the various
pack/unpack optabs but we have very many of those ... and the problem
extends to even/odd and lo/hi widen ops as well. I don't think
mass-changing those at this point is desirable (that definitely looks like
a stage1 problem).
As long as we don't have both we can circumvent the ICE with patches like
proposed. Fixed patch, "complete":
diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index d39dfc1065f..0fb21e58138 100644
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -47,6 +47,8 @@ along with GCC; see the file COPYING3. If not see
#include "tree-cfgcleanup.h"
#include "cfganal.h"
#include "optabs-tree.h"
+#include "insn-config.h"
+#include "recog.h"
#include "tree-vector-builder.h"
#include "vec-perm-indices.h"
#include "internal-fn.h"
@@ -2978,6 +2980,7 @@ simplify_vector_constructor (gimple_stmt_iterator *gsi)
/* Only few targets implement direct conversion patterns so try
some simple special cases via VEC_[UN]PACK[_FLOAT]_LO_EXPR. */
optab optab;
+ insn_code icode;
tree halfvectype, dblvectype;
enum tree_code unpack_op;
@@ -3015,8 +3018,9 @@ simplify_vector_constructor (gimple_stmt_iterator *gsi)
&& (optab = optab_for_tree_code (unpack_op,
dblvectype,
optab_default))
- && (optab_handler (optab, TYPE_MODE (dblvectype))
- != CODE_FOR_nothing))
+ && ((icode = optab_handler (optab, TYPE_MODE (dblvectype)))
+ != CODE_FOR_nothing)
+ && (insn_data[icode].operand[0].mode == TYPE_MODE (type)))
{
gimple_seq stmts = NULL;
tree dbl;
@@ -3054,8 +3058,9 @@ simplify_vector_constructor (gimple_stmt_iterator *gsi)
&& (optab = optab_for_tree_code (VEC_PACK_TRUNC_EXPR,
halfvectype,
optab_default))
- && (optab_handler (optab, TYPE_MODE (halfvectype))
- != CODE_FOR_nothing))
+ && ((icode = optab_handler (optab, TYPE_MODE (halfvectype)))
+ != CODE_FOR_nothing)
+ && (insn_data[icode].operand[0].mode == TYPE_MODE (type)))
{
gimple_seq stmts = NULL;
tree low = gimple_build (&stmts, BIT_FIELD_REF, halfvectype,
