Hello,
I am not 100% convinced that it is always better to fold to a MEM_REF, but
that's what the PR asks for.
bootstrap+testsuite on x86_64-linux-gnu.
2013-04-03 Marc Glisse <marc.gli...@inria.fr>
PR middle-end/52436
gcc/
* fold-const.c (fold_ternary_loc) <BIT_FIELD_REF>: Handle nested
reference.
gcc/testsuite/
* gcc.dg/pr52436.c: New testcase.
* gcc.dg/tree-ssa/ssa-fre-33.c: Adjust optimizer message.
* gcc.dg/tree-ssa/ssa-fre-34.c: Adjust optimizer message.
--
Marc GlisseIndex: gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-33.c
===================================================================
--- gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-33.c (revision 197411)
+++ gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-33.c (working copy)
@@ -11,12 +11,12 @@ struct {
float x;
int main(int argc)
{
vector float res = (vector float){0.0f,0.0f,0.0f,1.0f};
res += (vector float){1.0f,2.0f,3.0f,4.0f};
s.global_res = res;
x = *((float*)&s.global_res + 1);
return 0;
}
-/* { dg-final { scan-tree-dump "Replaced BIT_FIELD_REF.*with 2" "fre1" } } */
+/* { dg-final { scan-tree-dump "Replaced .* with 2" "fre1" } } */
/* { dg-final { cleanup-tree-dump "fre1" } } */
Index: gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-34.c
===================================================================
--- gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-34.c (revision 197411)
+++ gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-34.c (working copy)
@@ -8,12 +8,12 @@ struct {
float i;
vector float global_res;
} s;
float foo(float f)
{
vector float res = (vector float){0.0f,f,0.0f,1.0f};
s.global_res = res;
return *((float*)&s.global_res + 1);
}
-/* { dg-final { scan-tree-dump "Replaced BIT_FIELD_REF.*with f" "fre1" } } */
+/* { dg-final { scan-tree-dump "Replaced .* with f" "fre1" } } */
/* { dg-final { cleanup-tree-dump "fre1" } } */
Index: gcc/testsuite/gcc.dg/pr52436.c
===================================================================
--- gcc/testsuite/gcc.dg/pr52436.c (revision 0)
+++ gcc/testsuite/gcc.dg/pr52436.c (revision 0)
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-optimized" } */
+
+typedef long long __m128i __attribute__ ((vector_size (2 * sizeof (long long)),
+ may_alias));
+typedef struct
+{
+ __m128i b;
+} s_1a;
+typedef s_1a s_1m __attribute__((aligned(1)));
+void
+foo (s_1m *p)
+{
+ p->b[1] = 5;
+}
+
+/* { dg-final { scan-tree-dump-not "BIT_FIELD_EXPR" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
Property changes on: gcc/testsuite/gcc.dg/pr52436.c
___________________________________________________________________
Added: svn:keywords
+ Author Date Id Revision URL
Added: svn:eol-style
+ native
Index: gcc/fold-const.c
===================================================================
--- gcc/fold-const.c (revision 197411)
+++ gcc/fold-const.c (working copy)
@@ -14293,20 +14293,34 @@ fold_ternary_loc (location_t loc, enum t
{
tree v = native_interpret_expr (type,
b + bitpos / BITS_PER_UNIT,
bitsize / BITS_PER_UNIT);
if (v)
return v;
}
}
}
+ /* BIT_FIELD_REF[a.b, *, CST] -> MEM[&a, offsetof (a, b) + CST / 8]. */
+ if ((handled_component_p (arg0) || TREE_CODE (arg0) == MEM_REF)
+ && TREE_INT_CST_LOW (arg1) % BITS_PER_UNIT == 0
+ && TREE_INT_CST_LOW (arg2) % BITS_PER_UNIT == 0)
+ {
+ HOST_WIDE_INT coffset;
+ tree base = get_addr_base_and_unit_offset (arg0, &coffset);
+ if (base)
+ return fold_build2 (MEM_REF, type, build_fold_addr_expr (base),
+ build_int_cst (build_pointer_type
+ (TYPE_MAIN_VARIANT (type)),
+ coffset + TREE_INT_CST_LOW (arg2)
+ / BITS_PER_UNIT));
+ }
return NULL_TREE;
case FMA_EXPR:
/* For integers we can decompose the FMA if possible. */
if (TREE_CODE (arg0) == INTEGER_CST
&& TREE_CODE (arg1) == INTEGER_CST)
return fold_build2_loc (loc, PLUS_EXPR, type,
const_binop (MULT_EXPR, arg0, arg1), arg2);
if (integer_zerop (arg2))
return fold_build2_loc (loc, MULT_EXPR, type, arg0, arg1);
