http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59471
--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
Testing
Index: gimplify.c
===================================================================
--- gimplify.c (revision 205891)
+++ gimplify.c (working copy)
@@ -7358,12 +7358,22 @@ gimplify_expr (tree *expr_p, gimple_seq
TREE_TYPE (*expr_p));
break;
+ case VIEW_CONVERT_EXPR:
+ if (is_gimple_reg_type (TREE_TYPE (*expr_p))
+ && is_gimple_reg_type (TREE_TYPE (TREE_OPERAND (*expr_p, 0))))
+ {
+ ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
+ post_p, is_gimple_val, fb_rvalue);
+ recalculate_side_effects (*expr_p);
+ break;
+ }
+ /* Fallthru. */
+
case ARRAY_REF:
case ARRAY_RANGE_REF:
case REALPART_EXPR:
case IMAGPART_EXPR:
case COMPONENT_REF:
- case VIEW_CONVERT_EXPR:
ret = gimplify_compound_lval (expr_p, pre_p, post_p,
fallback ? fallback : fb_rvalue);
break;
@@ -7709,10 +7719,17 @@ gimplify_expr (tree *expr_p, gimple_seq
break;
case BIT_FIELD_REF:
- ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
- post_p, is_gimple_lvalue, fb_either);
- recalculate_side_effects (*expr_p);
- break;
+ {
+ if (is_gimple_reg_type (TREE_TYPE (*expr_p))
+ && is_gimple_reg_type (TREE_TYPE (TREE_OPERAND (*expr_p, 0))))
+ ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
+ post_p, is_gimple_val, fb_rvalue);
+ else
+ ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
+ post_p, is_gimple_lvalue, fb_either);
+ recalculate_side_effects (*expr_p);
+ break;
+ }
case TARGET_MEM_REF:
{
code-generation for the testcase is awkward though:
foo:
.LFB0:
.cfi_startproc
movaps %xmm0, -24(%rsp)
movq -24(%rsp), %rax
movq %rax, -24(%rsp)
movq -24(%rsp), %xmm0
ret
not sure why RTL cannot recover here, we expand from
foo (uint16x8_t x)
{
vector(2) long unsigned int _2;
long unsigned int _3;
uint8x8_t _4;
<bb 2>:
_2 = VIEW_CONVERT_EXPR<vector(2) long unsigned int>(x_5(D));
_3 = BIT_FIELD_REF <_2, 64, 0>;
_4 = VIEW_CONVERT_EXPR<uint8x8_t>(_3);
return _4;
with forwprop we could re-write this into
_4 = BIT_FIELD_REF <x_5(D), 64, 0>;
as BIT_FIELD_REF is allowed to select uint8x8_t from uint16x8_t directly.
