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re PR tree-optimization/49715 (Could do more efficient unsigned-to-float to conversions based on range information)

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2011-07-25  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/49715
	* tree-vrp.c: Include expr.h and optabs.h.
	(range_fits_type_): New function.
	(simplify_float_conversion_using_ranges): Likewise.
	(simplify_stmt_using_ranges): Call it.
	* Makefile.in (tree-vrp.o): Add $(EXPR_H) and $(OPTABS_H) dependencies.
	* optabs.c (can_float_p): Export.
	* optabs.h (can_float_p): Declare.

	* gcc.target/i386/pr49715-1.c: New testcase.
	* gcc.target/i386/pr49715-2.c: Likewise.

From-SVN: r176735
This commit is contained in:
Richard Guenther 2011-07-25 08:30:46 +00:00 • committed by Richard Biener
parent d92562770a
commit ebeadd9141
8 changed files with 144 additions and 2 deletions
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11
gcc/ChangeLog
View file

@ -1,3 +1,14 @@
2011-07-25 Richard Guenther <rguenther@suse.de>
PR tree-optimization/49715
* tree-vrp.c: Include expr.h and optabs.h.
(range_fits_type_): New function.
(simplify_float_conversion_using_ranges): Likewise.
(simplify_stmt_using_ranges): Call it.
* Makefile.in (tree-vrp.o): Add $(EXPR_H) and $(OPTABS_H) dependencies.
* optabs.c (can_float_p): Export.
* optabs.h (can_float_p): Declare.
2011-07-25 Richard Guenther <rguenther@suse.de>
* tree-vrp.c (num_vr_values, values_propagated): New global vars.

2
gcc/Makefile.in
View file

@ -2504,7 +2504,7 @@ tree-vrp.o : tree-vrp.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(TREE_H) \
$(TREE_FLOW_H) $(TREE_PASS_H) $(TREE_DUMP_H) $(DIAGNOSTIC_H) $(GGC_H) \
$(BASIC_BLOCK_H) tree-ssa-propagate.h $(FLAGS_H) $(TREE_DUMP_H) \
$(CFGLOOP_H) $(SCEV_H) $(TIMEVAR_H) intl.h tree-pretty-print.h \
gimple-pretty-print.h gimple-fold.h
gimple-pretty-print.h gimple-fold.h $(OPTABS_H) $(EXPR_H)
tree-cfg.o : tree-cfg.c $(TREE_FLOW_H) $(CONFIG_H) $(SYSTEM_H) \
$(TREE_H) $(TM_P_H) $(EXPR_H) $(GGC_H) $(FLAGS_H) output.h \
$(DIAGNOSTIC_H) $(FUNCTION_H) $(TIMEVAR_H) $(TM_H) coretypes.h \

2
gcc/optabs.c
View file

@ -4626,7 +4626,7 @@ can_fix_p (enum machine_mode fixmode, enum machine_mode fltmode,
return CODE_FOR_nothing;
}
static enum insn_code
enum insn_code
can_float_p (enum machine_mode fltmode, enum machine_mode fixmode,
int unsignedp)
{

3
gcc/optabs.h
View file

@ -849,6 +849,9 @@ extern void expand_fixed_convert (rtx, rtx, int, int);
/* Generate code for a FLOAT_EXPR. */
extern void expand_float (rtx, rtx, int);
/* Return the insn_code for a FLOAT_EXPR. */
enum insn_code can_float_p (enum machine_mode, enum machine_mode, int);
/* Generate code for a FIX_EXPR. */
extern void expand_fix (rtx, rtx, int);

6
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,9 @@
2011-07-25 Richard Guenther <rguenther@suse.de>
PR tree-optimization/49715
* gcc.target/i386/pr49715-1.c: New testcase.
* gcc.target/i386/pr49715-2.c: Likewise.
2011-07-23 Jason Merrill <jason@redhat.com>
* g++.dg/cpp0x/decltype21.C: Add 49823 examples.

9
gcc/testsuite/gcc.target/i386/pr49715-1.c Normal file
View file

@ -0,0 +1,9 @@
/* { dg-do compile } */
/* { dg-options "-O2 -msse -mfpmath=sse" } */
float func(unsigned x)
{
return (x & 0xfffff) * 0.01f;
}
/* { dg-final { scan-assembler-times "cvtsi2ss" 1 } } */

12
gcc/testsuite/gcc.target/i386/pr49715-2.c Normal file
View file

@ -0,0 +1,12 @@
/* { dg-do compile } */
/* { dg-require-effective-target lp64 } */
/* { dg-options "-O2" } */
double func(unsigned long long x)
{
if (x <= 0x7ffffffffffffffeULL)
return (x + 1) * 0.01;
return 0.0;
}
/* { dg-final { scan-assembler-times "cvtsi2sdq" 1 } } */

101
gcc/tree-vrp.c
View file

@ -40,6 +40,8 @@ along with GCC; see the file COPYING3. If not see
#include "tree-ssa-propagate.h"
#include "tree-chrec.h"
#include "gimple-fold.h"
#include "expr.h"
#include "optabs.h"
/* Type of value ranges. See value_range_d for a description of these
@ -7415,6 +7417,99 @@ simplify_conversion_using_ranges (gimple stmt)
return true;
}
/* Return whether the value range *VR fits in an integer type specified
by PRECISION and UNSIGNED_P. */
static bool
range_fits_type_p (value_range_t *vr, unsigned precision, bool unsigned_p)
{
double_int tem;
/* We can only handle constant ranges. */
if (vr->type != VR_RANGE
|| TREE_CODE (vr->min) != INTEGER_CST
|| TREE_CODE (vr->max) != INTEGER_CST)
return false;
tem = double_int_ext (tree_to_double_int (vr->min), precision, unsigned_p);
if (!double_int_equal_p (tree_to_double_int (vr->min), tem))
return false;
tem = double_int_ext (tree_to_double_int (vr->max), precision, unsigned_p);
if (!double_int_equal_p (tree_to_double_int (vr->max), tem))
return false;
return true;
}
/* Simplify a conversion from integral SSA name to float in STMT. */
static bool
simplify_float_conversion_using_ranges (gimple_stmt_iterator *gsi, gimple stmt)
{
tree rhs1 = gimple_assign_rhs1 (stmt);
value_range_t *vr = get_value_range (rhs1);
enum machine_mode fltmode = TYPE_MODE (TREE_TYPE (gimple_assign_lhs (stmt)));
enum machine_mode mode;
tree tem;
gimple conv;
/* We can only handle constant ranges. */
if (vr->type != VR_RANGE
|| TREE_CODE (vr->min) != INTEGER_CST
|| TREE_CODE (vr->max) != INTEGER_CST)
return false;
/* First check if we can use a signed type in place of an unsigned. */
if (TYPE_UNSIGNED (TREE_TYPE (rhs1))
&& (can_float_p (fltmode, TYPE_MODE (TREE_TYPE (rhs1)), 0)
!= CODE_FOR_nothing)
&& range_fits_type_p (vr, GET_MODE_PRECISION
(TYPE_MODE (TREE_TYPE (rhs1))), 0))
mode = TYPE_MODE (TREE_TYPE (rhs1));
/* If we can do the conversion in the current input mode do nothing. */
else if (can_float_p (fltmode, TYPE_MODE (TREE_TYPE (rhs1)),
TYPE_UNSIGNED (TREE_TYPE (rhs1))))
return false;
/* Otherwise search for a mode we can use, starting from the narrowest
integer mode available. */
else
{
mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
do
{
/* If we cannot do a signed conversion to float from mode
or if the value-range does not fit in the signed type
try with a wider mode. */
if (can_float_p (fltmode, mode, 0) != CODE_FOR_nothing
&& range_fits_type_p (vr, GET_MODE_PRECISION (mode), 0))
break;
mode = GET_MODE_WIDER_MODE (mode);
/* But do not widen the input. Instead leave that to the
optabs expansion code. */
if (GET_MODE_PRECISION (mode) > TYPE_PRECISION (TREE_TYPE (rhs1)))
return false;
}
while (mode != VOIDmode);
if (mode == VOIDmode)
return false;
}
/* It works, insert a truncation or sign-change before the
float conversion. */
tem = create_tmp_var (build_nonstandard_integer_type
(GET_MODE_PRECISION (mode), 0), NULL);
conv = gimple_build_assign_with_ops (NOP_EXPR, tem, rhs1, NULL_TREE);
tem = make_ssa_name (tem, conv);
gimple_assign_set_lhs (conv, tem);
gsi_insert_before (gsi, conv, GSI_SAME_STMT);
gimple_assign_set_rhs1 (stmt, tem);
update_stmt (stmt);
return true;
}
/* Simplify STMT using ranges if possible. */
static bool
@ -7474,6 +7569,12 @@ simplify_stmt_using_ranges (gimple_stmt_iterator *gsi)
return simplify_conversion_using_ranges (stmt);
break;
case FLOAT_EXPR:
if (TREE_CODE (rhs1) == SSA_NAME
&& INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
return simplify_float_conversion_using_ranges (gsi, stmt);
break;
default:
break;
}