On 14/09/2018 16:37, Richard Sandiford wrote:
diff --git a/gcc/combine.c b/gcc/combine.c
index a2649b6..cbf9dae 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -8621,7 +8621,13 @@ gen_lowpart_or_truncate (machine_mode mode, rtx x)
{
/* Bit-cast X into an integer mode. */
if (!SCALAR_INT_MODE_P (GET_MODE (x)))
- x = gen_lowpart (int_mode_for_mode (GET_MODE (x)).require (), x);
+ {
+ enum machine_mode imode =
+ int_mode_for_mode (GET_MODE (x)).require ();
+ if (imode == BLKmode)
+ return gen_rtx_CLOBBER (mode, const0_rtx);
+ x = gen_lowpart (imode, x);
require () will ICE if there isn't an integer mode and always returns
a scalar_int_mode, so this looks like a no-op. I think you want
something like:
This is a patch that I inherited from Honza and Martin and didn't know
what testcase it fixed.
I think that it being broken shows that it's no longer necessary, and
reverting the patch and retesting confirms this suspicion.
I've removed it from the patch.
@@ -11698,6 +11704,11 @@ gen_lowpart_for_combine (machine_mode omode, rtx x)
if (omode == imode)
return x;
+ /* This can happen when there is no integer mode corresponding
+ to a size of vector mode. */
+ if (omode == BLKmode)
+ goto fail;
+
/* We can only support MODE being wider than a word if X is a
constant integer or has a mode the same size. */
if (maybe_gt (GET_MODE_SIZE (omode), UNITS_PER_WORD)
This seems like it's working around a bug in ther caller.
Again, I inherited this hunk. Removing it and retesting shows no
regressions, so I'm dropping it.
diff --git a/gcc/expr.c b/gcc/expr.c
index cd5cf12..776254a 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -10569,6 +10569,14 @@ expand_expr_real_1 (tree exp, rtx target, machine_mode
tmode,
|| maybe_gt (bitpos + bitsize,
GET_MODE_BITSIZE (mode2)));
+ /* If the result is in BLKmode and the underlying object is a
+ vector in a register, and the size of the vector is larger than
+ the largest integer mode, then we must force OP0 to be in memory
+ as this is assumed in later code. */
+ if (REG_P (op0) && VECTOR_MODE_P (mode2) && mode == BLKmode
+ && maybe_gt (bitsize, MAX_FIXED_MODE_SIZE))
+ must_force_mem = 1;
+
/* Handle CONCAT first. */
if (GET_CODE (op0) == CONCAT && !must_force_mem)
{
Are you sure this is still needed after:
2018-06-04 Richard Sandiford <richard.sandif...@linaro.org>
* expr.c (expand_expr_real_1): Force the operand into memory if
its TYPE_MODE is BLKmode and if there is no integer mode for
the number of bits being extracted.
Apparently you're right about this. Hunk dropped.
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 8d94fca..607a2bd 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -6702,12 +6702,12 @@ vectorizable_store (stmt_vec_info stmt_info,
gimple_stmt_iterator *gsi,
supported. */
unsigned lsize
= group_size * GET_MODE_BITSIZE (elmode);
- elmode = int_mode_for_size (lsize, 0).require ();
unsigned int lnunits = const_nunits / group_size;
/* If we can't construct such a vector fall back to
element extracts from the original vector type and
element size stores. */
- if (mode_for_vector (elmode, lnunits).exists (&vmode)
+ if (int_mode_for_size (lsize, 0).exists (&elmode)
+ && mode_for_vector (elmode, lnunits).exists (&vmode)
&& VECTOR_MODE_P (vmode)
&& targetm.vector_mode_supported_p (vmode)
&& (convert_optab_handler (vec_extract_optab,
@@ -7839,11 +7839,11 @@ vectorizable_load (stmt_vec_info stmt_info,
gimple_stmt_iterator *gsi,
to a larger load. */
unsigned lsize
= group_size * TYPE_PRECISION (TREE_TYPE (vectype));
- elmode = int_mode_for_size (lsize, 0).require ();
unsigned int lnunits = const_nunits / group_size;
/* If we can't construct such a vector fall back to
element loads of the original vector type. */
- if (mode_for_vector (elmode, lnunits).exists (&vmode)
+ if (int_mode_for_size (lsize, 0).exists (&elmode)
+ && mode_for_vector (elmode, lnunits).exists (&vmode)
&& VECTOR_MODE_P (vmode)
&& targetm.vector_mode_supported_p (vmode)
&& (convert_optab_handler (vec_init_optab, vmode, elmode)
These two are OK independently of the rest (if that's convenient).
Thanks, I've committed the attached. These are the only parts of the
patch that remain. I've confirmed that there are failures without these
hunks.
Andrew
Handle vectors that don't fit in an integer.
GCN vector sizes range between 64 and 512 bytes, none of which have
correspondingly sized integer modes. This breaks a number of assumptions
throughout the compiler, but I don't really want to create modes just for this
purpose.
Instead, this patch fixes up the cases that I've found, so far, such that the
compiler tries something else, or fails to optimize, rather than just ICE.
2018-11-15 Andrew Stubbs <a...@codesourcery.com>
Kwok Cheung Yeung <k...@codesourcery.com>
gcc/
* tree-vect-stmts.c (vectorizable_store): Don't ICE when
int_mode_for_size fails.
(vectorizable_load): Likewise.
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 75d77d2..3509d29 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -6672,12 +6672,12 @@ vectorizable_store (stmt_vec_info stmt_info, gimple_stmt_iterator *gsi,
supported. */
unsigned lsize
= group_size * GET_MODE_BITSIZE (elmode);
- elmode = int_mode_for_size (lsize, 0).require ();
unsigned int lnunits = const_nunits / group_size;
/* If we can't construct such a vector fall back to
element extracts from the original vector type and
element size stores. */
- if (mode_for_vector (elmode, lnunits).exists (&vmode)
+ if (int_mode_for_size (lsize, 0).exists (&elmode)
+ && mode_for_vector (elmode, lnunits).exists (&vmode)
&& VECTOR_MODE_P (vmode)
&& targetm.vector_mode_supported_p (vmode)
&& (convert_optab_handler (vec_extract_optab,
@@ -7806,11 +7806,11 @@ vectorizable_load (stmt_vec_info stmt_info, gimple_stmt_iterator *gsi,
to a larger load. */
unsigned lsize
= group_size * TYPE_PRECISION (TREE_TYPE (vectype));
- elmode = int_mode_for_size (lsize, 0).require ();
unsigned int lnunits = const_nunits / group_size;
/* If we can't construct such a vector fall back to
element loads of the original vector type. */
- if (mode_for_vector (elmode, lnunits).exists (&vmode)
+ if (int_mode_for_size (lsize, 0).exists (&elmode)
+ && mode_for_vector (elmode, lnunits).exists (&vmode)
&& VECTOR_MODE_P (vmode)
&& targetm.vector_mode_supported_p (vmode)
&& (convert_optab_handler (vec_init_optab, vmode, elmode)
