The following patch fixes missing constant propagation in SSA propagators
and FRE. Noticed this when working on sth else.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2016-07-19 Richard Biener <rguent...@suse.de>
* gimple-fold.c (get_base_constructor): Add VIEW_CONVERT case,
handle all tcc_constant bases and valueize SSA names.
* tree-ssa-sccvn.c (fully_constant_vn_reference_p): Handle
tcc_constant bases.
* c-c++-common/vector-subscript-6.c: New testcase.
* c-c++-common/vector-subscript-7.c: Likewise.
Index: gcc/gimple-fold.c
===================================================================
*** gcc/gimple-fold.c (revision 238426)
--- gcc/gimple-fold.c (working copy)
*************** get_base_constructor (tree base, HOST_WI
*** 5508,5513 ****
--- 5499,5507 ----
return NULL_TREE;
base = TREE_OPERAND (base, 0);
}
+ else if (valueize
+ && TREE_CODE (base) == SSA_NAME)
+ base = valueize (base);
/* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its
DECL_INITIAL. If BASE is a nested reference into another
*************** get_base_constructor (tree base, HOST_WI
*** 5529,5534 ****
--- 5523,5532 ----
return init;
}
+ case VIEW_CONVERT_EXPR:
+ return get_base_constructor (TREE_OPERAND (base, 0),
+ bit_offset, valueize);
+
case ARRAY_REF:
case COMPONENT_REF:
base = get_ref_base_and_extent (base, &bit_offset2, &size, &max_size,
*************** get_base_constructor (tree base, HOST_WI
*** 5538,5548 ****
*bit_offset += bit_offset2;
return get_base_constructor (base, bit_offset, valueize);
- case STRING_CST:
case CONSTRUCTOR:
return base;
default:
return NULL_TREE;
}
}
--- 5536,5548 ----
*bit_offset += bit_offset2;
return get_base_constructor (base, bit_offset, valueize);
case CONSTRUCTOR:
return base;
default:
+ if (CONSTANT_CLASS_P (base))
+ return base;
+
return NULL_TREE;
}
}
Index: gcc/tree-ssa-sccvn.c
===================================================================
*** gcc/tree-ssa-sccvn.c (revision 238426)
--- gcc/tree-ssa-sccvn.c (working copy)
*************** fully_constant_vn_reference_p (vn_refere
*** 1331,1336 ****
--- 1337,1347 ----
unsigned i;
for (i = 0; i < operands.length (); ++i)
{
+ if (TREE_CODE_CLASS (operands[i].opcode) == tcc_constant)
+ {
+ ++i;
+ break;
+ }
if (operands[i].off == -1)
return NULL_TREE;
off += operands[i].off;
Index: gcc/testsuite/c-c++-common/vector-subscript-6.c
===================================================================
*** gcc/testsuite/c-c++-common/vector-subscript-6.c (revision 0)
--- gcc/testsuite/c-c++-common/vector-subscript-6.c (working copy)
***************
*** 0 ****
--- 1,14 ----
+ /* { dg-do compile } */
+ /* { dg-options "-O -fno-tree-ccp -fdump-tree-fre1" } */
+
+ typedef int v4si __attribute__ ((vector_size (16)));
+
+ int
+ main (int argc, char** argv)
+ {
+ int i = 2;
+ int j = ((v4si){0, 1, 2, 3})[i];
+ return ((v4si){1, 2, 42, 0})[j];
+ }
+
+ /* { dg-final { scan-tree-dump "return 42;" "fre1" } } */
Index: gcc/testsuite/c-c++-common/vector-subscript-7.c
===================================================================
*** gcc/testsuite/c-c++-common/vector-subscript-7.c (revision 0)
--- gcc/testsuite/c-c++-common/vector-subscript-7.c (working copy)
***************
*** 0 ****
--- 1,14 ----
+ /* { dg-do compile } */
+ /* { dg-options "-O -fdump-tree-ccp1" } */
+
+ typedef int v4si __attribute__ ((vector_size (16)));
+
+ int
+ main (int argc, char** argv)
+ {
+ int i = 2;
+ int j = ((v4si){0, 1, 2, 3})[i];
+ return ((v4si){1, 2, 42, 0})[j];
+ }
+
+ /* { dg-final { scan-tree-dump "return 42;" "ccp1" } } */
