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riscv-gcc-1
Commit ee2e8462 by Eric Botcazou
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cfgexpand.c (defer_stack_allocation): When optimization is enabled... 

	* cfgexpand.c (defer_stack_allocation): When optimization is enabled,
	defer allocation of DECL_IGNORED_P variables at toplevel unless really
	small.  Factorize size threshold computation from the existing one.
	(expand_used_vars): Refine comment.

From-SVN: r204830
parent ed1fc0bc
Showing with 111 additions and 8 deletions
gcc/ChangeLog
2013-11-14 Olivier Hainque <hainque@adacore.com>
* cfgexpand.c (defer_stack_allocation): When optimization is enabled,
defer allocation of DECL_IGNORED_P variables at toplevel unless really
small. Factorize size threshold computation from the existing one.
(expand_used_vars): Refine comment.
2013-11-14 Cong Hou <congh@google.com>
* tree-vectorizer.h (struct dr_with_seg_len): Remove the base
gcc/cfgexpand.c
......@@ -1130,6 +1130,12 @@ expand_one_error_var (tree var)
static bool
defer_stack_allocation (tree var, bool toplevel)
{
/* Whether the variable is small enough for immediate allocation not to be
a problem with regard to the frame size. */
bool smallish
= (tree_low_cst (DECL_SIZE_UNIT (var), 1)
< PARAM_VALUE (PARAM_MIN_SIZE_FOR_STACK_SHARING));
/* If stack protection is enabled, *all* stack variables must be deferred,
so that we can re-order the strings to the top of the frame.
Similarly for Address Sanitizer. */
......@@ -1141,8 +1147,15 @@ defer_stack_allocation (tree var, bool toplevel)
if (DECL_ALIGN (var) > MAX_SUPPORTED_STACK_ALIGNMENT)
return true;
/* Variables in the outermost scope automatically conflict with
every other variable. The only reason to want to defer them
/* When optimization is enabled, DECL_IGNORED_P variables originally scoped
might be detached from their block and appear at toplevel when we reach
here. We want to coalesce them with variables from other blocks when
the immediate contribution to the frame size would be noticeable. */
if (toplevel && optimize > 0 && DECL_IGNORED_P (var) && !smallish)
return true;
/* Variables declared in the outermost scope automatically conflict
with every other variable. The only reason to want to defer them
at all is that, after sorting, we can more efficiently pack
small variables in the stack frame. Continue to defer at -O2. */
if (toplevel && optimize < 2)
......@@ -1154,9 +1167,7 @@ defer_stack_allocation (tree var, bool toplevel)
other hand, we don't want the function's stack frame size to
get completely out of hand. So we avoid adding scalars and
"small" aggregates to the list at all. */
if (optimize == 0
&& (tree_low_cst (DECL_SIZE_UNIT (var), 1)
< PARAM_VALUE (PARAM_MIN_SIZE_FOR_STACK_SHARING)))
if (optimize == 0 && smallish)
return false;
return true;
......@@ -1676,9 +1687,11 @@ expand_used_vars (void)
else if (TREE_STATIC (var) || DECL_EXTERNAL (var))
expand_now = true;
/* If the variable is not associated with any block, then it
was created by the optimizers, and could be live anywhere
in the function. */
/* Expand variables not associated with any block now. Those created by
the optimizers could be live anywhere in the function. Those that
could possibly have been scoped originally and detached from their
block will have their allocation deferred so we coalesce them with
others when optimization is enabled. */
else if (TREE_USED (var))
expand_now = true;
......
gcc/testsuite/ChangeLog
2013-11-14 Eric Botcazou <ebotcazou@adacore.com>
* gnat.dg/stack_usage1b.adb: New test.
* gnat.dg/stack_usage1c.adb: Likewise.
2013-11-14 H.J. Lu <hongjiu.lu@intel.com>
* gnat.dg/specs/addr1.ads: Revert the last change.
......
gcc/testsuite/gnat.dg/stack_usage1b.adb 0 → 100644
-- { dg-do compile }
-- { dg-options "-O -fstack-usage" }
with Stack_Usage1_Pkg; use Stack_Usage1_Pkg;
procedure Stack_Usage1b is
A : Integer := Ident_Int (123);
begin
case A is
when 0 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 1 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 2 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 3 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 4 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 5 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 6 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 7 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 8 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 9 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when others =>
null;
end case;
end Stack_Usage1b;
-- { dg-final { scan-stack-usage "\t\[0-9\]\[0-9\]\t" { target i?86-*-* x86_64-*-* } } }
-- { dg-final { cleanup-stack-usage } }
gcc/testsuite/gnat.dg/stack_usage1c.adb 0 → 100644
-- { dg-do compile }
-- { dg-options "-O2 -fstack-usage" }
with Stack_Usage1_Pkg; use Stack_Usage1_Pkg;
procedure Stack_Usage1c is
A : Integer := Ident_Int (123);
begin
case A is
when 0 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 1 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 2 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 3 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 4 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 5 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 6 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 7 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 8 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when 9 =>
My_Proc (R'(Ident_Int(0), Ident_Int(1), Ident_Int(2), Ident_Int(3), Ident_Int(4), Ident_Int(5), Ident_Int(6), Ident_Int(7), Ident_Int(8), Ident_Int(9)));
when others =>
null;
end case;
end Stack_Usage1c;
-- { dg-final { scan-stack-usage "\t\[0-9\]\[0-9\]\t" { target i?86-*-* x86_64-*-* } } }
-- { dg-final { cleanup-stack-usage } }
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