[PATCH] Fix PR49715, (float)unsigned -> (float)signed
Richard Guenther
rguenther@suse.de
Fri Jul 22 12:17:00 GMT 2011
On Fri, 22 Jul 2011, Richard Guenther wrote:
> On Fri, 22 Jul 2011, Richard Guenther wrote:
>
> > On Thu, 21 Jul 2011, Joseph S. Myers wrote:
> >
> > > On Thu, 21 Jul 2011, Richard Guenther wrote:
> > >
> > > > Patch also handling wider modes and not starting with SImode but
> > > > the mode of int:
> > >
> > > Use of target int for anything not about C ABIs is certainly wrong. This
> > > might be about what operations the target does efficiently, or what
> > > functions are present in libgcc (both of which would be functions of
> > > machine modes), but it's not about the choice of C int.
> >
> > Ok. Given rths last suggestion I'm testing the following which
> > checks all integer modes (but never will widen - optabs.c will do
> > that if it turns out to be profitable).
>
> Err, I should refresh the patch before sending it ... here it goes.
Regresses vectorization on i?86 because that defines floathi expanders
but the vectorizer does not recognize a short -> float conversion
as that requires different sized vectors (the int -> short truncation
is also a complication for it). One of the cases that fail to vectorize
is
#define N 40
float image[N][N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__)));
float out[N];
/* Outer-loop vectorization. */
__attribute__ ((noinline)) void
foo (){
int i,j;
for (i = 0; i < N; i++) {
for (j = 0; j < N; j++) {
image[j][i] = j+i;
}
}
}
where VRP figures out that j+i can be represented as a short.
Now, I can dumb down the VRP code to only consider doing the
unsigned -> signed demotion and never truncate (unless maybe
the target does not support floatMODE of the current input mode).
Other suggestions?
Thanks,
Richard.
> Richard.
>
> 2011-07-22 Richard Guenther <rguenther@suse.de>
>
> PR tree-optimization/49715
> * tree-vrp.c: Include expr.h and optabs.h.
> (simplify_float_conversion_using_ranges): New function.
> (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.
>
> Index: gcc/tree-vrp.c
> ===================================================================
> *** gcc/tree-vrp.c.orig 2011-07-21 17:46:16.000000000 +0200
> --- gcc/tree-vrp.c 2011-07-22 11:09:03.000000000 +0200
> *************** along with GCC; see the file COPYING3.
> *** 40,45 ****
> --- 40,47 ----
> #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
> *************** simplify_conversion_using_ranges (gimple
> *** 7448,7453 ****
> --- 7450,7520 ----
> 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;
> +
> + /* Search for a mode we can use. */
> + mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
> + do
> + {
> + double_int tem;
> +
> + /* 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)
> + {
> + tem = double_int_ext (tree_to_double_int (vr->min),
> + GET_MODE_PRECISION (mode), 0);
> + if (double_int_equal_p (tree_to_double_int (vr->min), tem))
> + {
> + tem = double_int_ext (tree_to_double_int (vr->max),
> + GET_MODE_PRECISION (mode), 0);
> + if (double_int_equal_p (tree_to_double_int (vr->max), tem))
> + 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
> *************** simplify_stmt_using_ranges (gimple_stmt_
> *** 7507,7512 ****
> --- 7574,7585 ----
> 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;
> }
> Index: gcc/testsuite/gcc.target/i386/pr49715-1.c
> ===================================================================
> *** /dev/null 1970-01-01 00:00:00.000000000 +0000
> --- gcc/testsuite/gcc.target/i386/pr49715-1.c 2011-07-21 17:46:39.000000000 +0200
> ***************
> *** 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 } } */
> Index: gcc/testsuite/gcc.target/i386/pr49715-2.c
> ===================================================================
> *** /dev/null 1970-01-01 00:00:00.000000000 +0000
> --- gcc/testsuite/gcc.target/i386/pr49715-2.c 2011-07-21 17:46:39.000000000 +0200
> ***************
> *** 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 } } */
> Index: gcc/Makefile.in
> ===================================================================
> *** gcc/Makefile.in.orig 2011-07-19 12:59:09.000000000 +0200
> --- gcc/Makefile.in 2011-07-22 11:09:16.000000000 +0200
> *************** tree-vrp.o : tree-vrp.c $(CONFIG_H) $(SY
> *** 2504,2510 ****
> $(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
> 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 \
> --- 2504,2510 ----
> $(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 $(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 \
> Index: gcc/optabs.c
> ===================================================================
> *** gcc/optabs.c.orig 2011-07-11 17:02:51.000000000 +0200
> --- gcc/optabs.c 2011-07-22 11:04:42.000000000 +0200
> *************** can_fix_p (enum machine_mode fixmode, en
> *** 4626,4632 ****
> return CODE_FOR_nothing;
> }
>
> ! static enum insn_code
> can_float_p (enum machine_mode fltmode, enum machine_mode fixmode,
> int unsignedp)
> {
> --- 4626,4632 ----
> return CODE_FOR_nothing;
> }
>
> ! enum insn_code
> can_float_p (enum machine_mode fltmode, enum machine_mode fixmode,
> int unsignedp)
> {
> Index: gcc/optabs.h
> ===================================================================
> *** gcc/optabs.h.orig 2011-06-22 16:01:28.000000000 +0200
> --- gcc/optabs.h 2011-07-22 11:06:01.000000000 +0200
> *************** extern void expand_fixed_convert (rtx, r
> *** 849,854 ****
> --- 849,857 ----
> /* 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);
>
>
--
Richard Guenther <rguenther@suse.de>
Novell / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer
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