GCSE: Use HOST_WIDE_INT instead of int (PR, rtl-optimization/79574).

GCSE: Use HOST_WIDE_INT instead of int (PR, rtl-optimization/79574).

[Martin Liška]

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Hello.

This is second part of fixes needed to not trigger integer overflow in gcse pass.

Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.

Ready to be installed?
Martin

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From a3e8ca75be55bd6d707f54ae3972e30285b64566 Mon Sep 17 00:00:00 2001
From: marxin <mliska@suse.cz>
Date: Thu, 2 Mar 2017 12:21:07 +0100
Subject: [PATCH] GCSE: Use HOST_WIDE_INT instead of int (PR
 rtl-optimization/79574).

gcc/ChangeLog:

2017-03-02  Martin Liska  <mliska@suse.cz>

	PR rtl-optimization/79574
	* gcse.c (struct gcse_expr): Use HOST_WIDE_INT instead of int.
	(hash_scan_set): Likewise.
	(dump_hash_table): Likewise.
	(hoist_code): Likewise.

gcc/testsuite/ChangeLog:

2017-03-02  Martin Liska  <mliska@suse.cz>

	PR rtl-optimization/79574
	* gcc.dg/pr79574-2.c: New test.
---
 gcc/gcse.c                       | 26 +++++++++++++++-----------
 gcc/testsuite/gcc.dg/pr79574-2.c | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 11 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/pr79574-2.c

diff --git a/gcc/gcse.c b/gcc/gcse.c
index 5c6984c3240..2b0a11268eb 100644
--- a/gcc/gcse.c
+++ b/gcc/gcse.c
@@ -281,7 +281,7 @@ struct gcse_expr
      to keep register pressure under control.
      A value of "0" removes restrictions on how far the expression can
      travel.  */
-  int max_distance;
+  HOST_WIDE_INT max_distance;
 };
 
 /* Occurrence of an expression.
@@ -458,7 +458,7 @@ static int oprs_unchanged_p (const_rtx, const rtx_insn *, int);
 static int oprs_anticipatable_p (const_rtx, const rtx_insn *);
 static int oprs_available_p (const_rtx, const rtx_insn *);
 static void insert_expr_in_table (rtx, machine_mode, rtx_insn *, int, int,
-				  int, struct gcse_hash_table_d *);
+				  HOST_WIDE_INT, struct gcse_hash_table_d *);
 static unsigned int hash_expr (const_rtx, machine_mode, int *, int);
 static void record_last_reg_set_info (rtx_insn *, int);
 static void record_last_mem_set_info (rtx_insn *);
@@ -488,8 +488,10 @@ static void alloc_code_hoist_mem (int, int);
 static void free_code_hoist_mem (void);
 static void compute_code_hoist_vbeinout (void);
 static void compute_code_hoist_data (void);
-static int should_hoist_expr_to_dom (basic_block, struct gcse_expr *, basic_block,
-				     sbitmap, int, int *, enum reg_class,
+static int should_hoist_expr_to_dom (basic_block, struct gcse_expr *,
+				     basic_block,
+				     sbitmap, HOST_WIDE_INT, int *,
+				     enum reg_class,
 				     int *, bitmap, rtx_insn *);
 static int hoist_code (void);
 static enum reg_class get_regno_pressure_class (int regno, int *nregs);
@@ -743,7 +745,7 @@ static basic_block current_bb;
    GCSE.  */
 
 static int
-want_to_gcse_p (rtx x, machine_mode mode, int *max_distance_ptr)
+want_to_gcse_p (rtx x, machine_mode mode, HOST_WIDE_INT *max_distance_ptr)
 {
 #ifdef STACK_REGS
   /* On register stack architectures, don't GCSE constants from the
@@ -1115,7 +1117,8 @@ expr_equiv_p (const_rtx x, const_rtx y)
 static void
 insert_expr_in_table (rtx x, machine_mode mode, rtx_insn *insn,
 		      int antic_p,
-		      int avail_p, int max_distance, struct gcse_hash_table_d *table)
+		      int avail_p, HOST_WIDE_INT max_distance,
+		      struct gcse_hash_table_d *table)
 {
   int found, do_not_record_p;
   unsigned int hash;
@@ -1231,7 +1234,7 @@ hash_scan_set (rtx set, rtx_insn *insn, struct gcse_hash_table_d *table)
   else if (REG_P (dest))
     {
       unsigned int regno = REGNO (dest);
-      int max_distance = 0;
+      HOST_WIDE_INT max_distance = 0;
 
       /* See if a REG_EQUAL note shows this equivalent to a simpler expression.
 
@@ -1300,7 +1303,7 @@ hash_scan_set (rtx set, rtx_insn *insn, struct gcse_hash_table_d *table)
   else if (flag_gcse_las && REG_P (src) && MEM_P (dest))
     {
       unsigned int regno = REGNO (src);
-      int max_distance = 0;
+      HOST_WIDE_INT max_distance = 0;
 
       /* Only record sets of pseudo-regs in the hash table.  */
       if (regno >= FIRST_PSEUDO_REGISTER
@@ -1413,7 +1416,7 @@ dump_hash_table (FILE *file, const char *name, struct gcse_hash_table_d *table)
       {
 	expr = flat_table[i];
 	fprintf (file, "Index %d (hash value %d; max distance %d)\n  ",
-		 expr->bitmap_index, hash_val[i], expr->max_distance);
+		 expr->bitmap_index, hash_val[i], (int)expr->max_distance);
 	print_rtl (file, expr->expr);
 	fprintf (file, "\n");
       }
@@ -2884,7 +2887,8 @@ update_bb_reg_pressure (basic_block bb, rtx_insn *from)
 
 static int
 should_hoist_expr_to_dom (basic_block expr_bb, struct gcse_expr *expr,
-			  basic_block bb, sbitmap visited, int distance,
+			  basic_block bb, sbitmap visited,
+			  HOST_WIDE_INT distance,
 			  int *bb_size, enum reg_class pressure_class,
 			  int *nregs, bitmap hoisted_bbs, rtx_insn *from)
 {
@@ -3161,7 +3165,7 @@ hoist_code (void)
 		 computes the expression.  */
 	      FOR_EACH_VEC_ELT (domby, j, dominated)
 		{
-		  int max_distance;
+		  HOST_WIDE_INT max_distance;
 
 		  /* Ignore self dominance.  */
 		  if (bb == dominated)
diff --git a/gcc/testsuite/gcc.dg/pr79574-2.c b/gcc/testsuite/gcc.dg/pr79574-2.c
new file mode 100644
index 00000000000..995dff40174
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr79574-2.c
@@ -0,0 +1,33 @@
+/* PR rtl-optimization/79574 */
+/* { dg-do compile } */
+/* { dg-options "-Os --param gcse-cost-distance-ratio=2147483647" } */
+
+#include "stdarg.h"
+
+int buf[100];
+int buf1[10];
+
+int rd (int *pppp, int n, ...)
+{
+  va_list argp;
+  int *p;
+  int i;
+  int res;
+
+  va_start (argp, n);
+  for (; n > 0; n--)
+    va_arg (argp, double);
+  p = va_arg (argp, int *);
+  i = va_arg (argp, int);
+
+  res = p[i];
+  __builtin_printf ("%d\n", res);
+
+  return res;
+}
+
+int mpx_test (int argc, const char **argv)
+{
+  rd (buf1, 2, 10.0d, 10.0d, buf, 100, buf1);
+  return 0;
+}
-- 
2.11.1

Re: GCSE: Use HOST_WIDE_INT instead of int (PR, rtl-optimization/79574).

[Bernd Schmidt]

On 03/02/2017 06:50 PM, Martin Liška wrote:
> Hello.
>
> This is second part of fixes needed to not trigger integer overflow in gcse pass.

So, how is this intended to work? The min/max stored in the param is an 
int, and by using a HOST_WIDE_INT here, we expect that it is a larger 
type and therefore won't overflow?

>        {
>  	expr = flat_table[i];
>  	fprintf (file, "Index %d (hash value %d; max distance %d)\n  ",
> -		 expr->bitmap_index, hash_val[i], expr->max_distance);
> +		 expr->bitmap_index, hash_val[i], (int)expr->max_distance);
>  	print_rtl (file, expr->expr);
>  	fprintf (file, "\n");

Use HOST_WIDE_INT_PRINT_DEC maybe? Otherwise OK, I guess.


Bernd

Re: GCSE: Use HOST_WIDE_INT instead of int (PR, rtl-optimization/79574).

[Martin Liška]

On 03/02/2017 08:58 PM, Bernd Schmidt wrote:
> On 03/02/2017 06:50 PM, Martin Liška wrote:
>> Hello.
>>
>> This is second part of fixes needed to not trigger integer overflow in gcse pass.
> 
> So, how is this intended to work? The min/max stored in the param is an int, and by using a HOST_WIDE_INT here, we expect that it is a larger type and therefore won't overflow?

Using int type is fine, but as gcse.c does an arithmetic with a distance:

	  /* Prefer to hoist EXPR if register pressure is decreased.  */
	  if (decreased_pressure > *nregs)
	    distance += bb_size[bb->index];

...

		    max_distance += (bb_size[dominated->index]
				     - to_bb_head[INSN_UID (occr->insn)]);


> 
>>        {
>>      expr = flat_table[i];
>>      fprintf (file, "Index %d (hash value %d; max distance %d)\n  ",
>> -         expr->bitmap_index, hash_val[i], expr->max_distance);
>> +         expr->bitmap_index, hash_val[i], (int)expr->max_distance);
>>      print_rtl (file, expr->expr);
>>      fprintf (file, "\n");
> 
> Use HOST_WIDE_INT_PRINT_DEC maybe? Otherwise OK, I guess.

That's for nit, I'll install the patch with that.

Martin

> 
> 
> Bernd

Re: GCSE: Use HOST_WIDE_INT instead of int (PR, rtl-optimization/79574).

[Richard Biener]

On Thu, Mar 2, 2017 at 8:58 PM, Bernd Schmidt <bschmidt@redhat.com> wrote:
> On 03/02/2017 06:50 PM, Martin Liška wrote:
>>
>> Hello.
>>
>> This is second part of fixes needed to not trigger integer overflow in
>> gcse pass.
>
>
> So, how is this intended to work? The min/max stored in the param is an int,
> and by using a HOST_WIDE_INT here, we expect that it is a larger type and
> therefore won't overflow?

HOST_WIDE_INT is equal to uint64_t (and we could mass-replace where we can
do so consistently)

Richard.

>>        {
>>         expr = flat_table[i];
>>         fprintf (file, "Index %d (hash value %d; max distance %d)\n  ",
>> -                expr->bitmap_index, hash_val[i], expr->max_distance);
>> +                expr->bitmap_index, hash_val[i],
>> (int)expr->max_distance);
>>         print_rtl (file, expr->expr);
>>         fprintf (file, "\n");
>
>
> Use HOST_WIDE_INT_PRINT_DEC maybe? Otherwise OK, I guess.
>
>
> Bernd