diff mbox series

gimple-ssa-warn-restrict: Only use type range from NOP_EXPR for non-narrowing conversions [PR113463]

Message ID Zao3/6vlO00aAaRA@tucnak
State Unresolved
Headers
Series gimple-ssa-warn-restrict: Only use type range from NOP_EXPR for non-narrowing conversions [PR113463] |

Checks

Context Check Description
snail/gcc-patch-check warning Git am fail log

Commit Message

Jakub Jelinek Jan. 19, 2024, 8:51 a.m. UTC 
  Hi!

builtin_memref::extend_offset_range when it sees a NOP_EXPR from
INTEGRAL_TYPE (to INTEGRAL_TYPE of sizetype/ptrdifftype precision
given the callers) uses wi::to_offset on TYPE_{MIN,MAX}_VALUE
of the rhs1 type.  This ICEs with large BITINT_TYPEs - to_offset
is only supported for precisions up to the offset_int precision
- but it even doesn't make any sense to do such thing for narrowing
conversions, their range means the whole sizetype/ptrdifftype range
and so the normal handling done later on (largest sized supported object)
is the way to go in that case.

So, the following patch just restrict this to non-narrowing conversions.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2024-01-19  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/113463
	* gimple-ssa-warn-restrict.cc (builtin_memref::extend_offset_range):
	Only look through NOP_EXPRs if rhs1 doesn't have wider type than
	lhs.

	* gcc.dg/bitint-74.c: New test.


	Jakub

Comments

Richard Biener Jan. 19, 2024, 8:55 a.m. UTC | #1 
On Fri, 19 Jan 2024, Jakub Jelinek wrote:

> Hi!
> 
> builtin_memref::extend_offset_range when it sees a NOP_EXPR from
> INTEGRAL_TYPE (to INTEGRAL_TYPE of sizetype/ptrdifftype precision
> given the callers) uses wi::to_offset on TYPE_{MIN,MAX}_VALUE
> of the rhs1 type.  This ICEs with large BITINT_TYPEs - to_offset
> is only supported for precisions up to the offset_int precision
> - but it even doesn't make any sense to do such thing for narrowing
> conversions, their range means the whole sizetype/ptrdifftype range
> and so the normal handling done later on (largest sized supported object)
> is the way to go in that case.
> 
> So, the following patch just restrict this to non-narrowing conversions.
> 
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

OK.

> 2024-01-19  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR tree-optimization/113463
> 	* gimple-ssa-warn-restrict.cc (builtin_memref::extend_offset_range):
> 	Only look through NOP_EXPRs if rhs1 doesn't have wider type than
> 	lhs.
> 
> 	* gcc.dg/bitint-74.c: New test.
> 
> --- gcc/gimple-ssa-warn-restrict.cc.jj	2024-01-03 11:51:27.705784291 +0100
> +++ gcc/gimple-ssa-warn-restrict.cc	2024-01-18 16:00:02.519483821 +0100
> @@ -391,7 +391,8 @@ builtin_memref::extend_offset_range (tre
>        tree type;
>        if (is_gimple_assign (stmt)
>  	  && (type = TREE_TYPE (gimple_assign_rhs1 (stmt)))
> -	  && INTEGRAL_TYPE_P (type))
> +	  && INTEGRAL_TYPE_P (type)
> +	  && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (offset)))
>  	{
>  	  tree_code code = gimple_assign_rhs_code (stmt);
>  	  if (code == NOP_EXPR)
> --- gcc/testsuite/gcc.dg/bitint-74.c.jj	2024-01-18 16:14:05.523599054 +0100
> +++ gcc/testsuite/gcc.dg/bitint-74.c	2024-01-18 16:13:30.150099638 +0100
> @@ -0,0 +1,16 @@
> +/* PR tree-optimization/113463 */
> +/* { dg-do compile { target bitint } } */
> +/* { dg-options "-std=c23 -O2" } */
> +
> +extern char *a, *b;
> +#if __BITINT_MAXWIDTH__ >= 129
> +_BitInt(129) o;
> +#else
> +_BitInt(63) o;
> +#endif
> +
> +void
> +foo (void)
> +{
> +  __builtin_memcpy (a + o, b, 4);
> +}
> 
> 	Jakub
> 
>
diff mbox series

Patch

--- gcc/gimple-ssa-warn-restrict.cc.jj	2024-01-03 11:51:27.705784291 +0100
+++ gcc/gimple-ssa-warn-restrict.cc	2024-01-18 16:00:02.519483821 +0100
@@ -391,7 +391,8 @@  builtin_memref::extend_offset_range (tre
       tree type;
       if (is_gimple_assign (stmt)
 	  && (type = TREE_TYPE (gimple_assign_rhs1 (stmt)))
-	  && INTEGRAL_TYPE_P (type))
+	  && INTEGRAL_TYPE_P (type)
+	  && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (offset)))
 	{
 	  tree_code code = gimple_assign_rhs_code (stmt);
 	  if (code == NOP_EXPR)
--- gcc/testsuite/gcc.dg/bitint-74.c.jj	2024-01-18 16:14:05.523599054 +0100
+++ gcc/testsuite/gcc.dg/bitint-74.c	2024-01-18 16:13:30.150099638 +0100
@@ -0,0 +1,16 @@ 
+/* PR tree-optimization/113463 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-std=c23 -O2" } */
+
+extern char *a, *b;
+#if __BITINT_MAXWIDTH__ >= 129
+_BitInt(129) o;
+#else
+_BitInt(63) o;
+#endif
+
+void
+foo (void)
+{
+  __builtin_memcpy (a + o, b, 4);
+}