diff mbox series

[GRAPHITE] Fix affine constraint generation

Message ID alpine.LSU.2.20.1709191028290.26836@zhemvz.fhfr.qr
State New
Headers show
Series [GRAPHITE] Fix affine constraint generation | expand

Commit Message

Richard Biener Sept. 19, 2017, 8:30 a.m. UTC 
The following plugs some holes in extract_affine which failed
to modulo-reduce signed values in conversions, failed to
interpret pointer-plus offsets as signed (yeah, stupid GIMPLE IL...)
and mishandled BIT_NOT_EXPR.

Bootstrap and regtest running on x86_64-unknown-linux-gnu.

Ok?

Thanks,
Richard.

2017-09-19  Richard Biener  <rguenther@suse.de>

	* graphite-sese-to-poly.c (extract_affine): Properly handle
	POINTER_PLUS_EXPR, BIT_NOT_EXPR and conversion to signed.

Comments

Sebastian Pop Sept. 19, 2017, 3:50 p.m. UTC | #1 
On Tue, Sep 19, 2017 at 3:30 AM, Richard Biener <rguenther@suse.de> wrote:

>
> The following plugs some holes in extract_affine which failed
> to modulo-reduce signed values in conversions, failed to
> interpret pointer-plus offsets as signed (yeah, stupid GIMPLE IL...)
> and mishandled BIT_NOT_EXPR.
>
> Bootstrap and regtest running on x86_64-unknown-linux-gnu.
>
> Ok?
>
> Thanks,
> Richard.
>
> 2017-09-19  Richard Biener  <rguenther@suse.de>
>
>         * graphite-sese-to-poly.c (extract_affine): Properly handle
>         POINTER_PLUS_EXPR, BIT_NOT_EXPR and conversion to signed.
>

This patch looks good to me.

Thanks,
Sebastian
diff mbox series

Patch

Index: gcc/graphite-sese-to-poly.c
===================================================================
--- gcc/graphite-sese-to-poly.c	(revision 252968)
+++ gcc/graphite-sese-to-poly.c	(working copy)
@@ -237,6 +237,7 @@  extract_affine (scop_p s, tree e, __isl_
     return NULL;
   }
 
+  tree type = TREE_TYPE (e);
   switch (TREE_CODE (e))
     {
     case POLYNOMIAL_CHREC:
@@ -247,8 +248,22 @@  extract_affine (scop_p s, tree e, __isl_
       res = extract_affine_mul (s, e, space);
       break;
 
-    case PLUS_EXPR:
     case POINTER_PLUS_EXPR:
+      {
+	lhs = extract_affine (s, TREE_OPERAND (e, 0), isl_space_copy (space));
+	/* The RHS of a pointer-plus expression is to be interpreted
+	   as signed value.  Try to look through a sign-changing conversion
+	   first.  */
+	tree tem = TREE_OPERAND (e, 1);
+	STRIP_NOPS (tem);
+	rhs = extract_affine (s, tem, space);
+	if (TYPE_UNSIGNED (TREE_TYPE (tem)))
+	  rhs = wrap (rhs, TYPE_PRECISION (type) - 1);
+	res = isl_pw_aff_add (lhs, rhs);
+	break;
+      }
+
+    case PLUS_EXPR:
       lhs = extract_affine (s, TREE_OPERAND (e, 0), isl_space_copy (space));
       rhs = extract_affine (s, TREE_OPERAND (e, 1), space);
       res = isl_pw_aff_add (lhs, rhs);
@@ -260,8 +275,13 @@  extract_affine (scop_p s, tree e, __isl_
       res = isl_pw_aff_sub (lhs, rhs);
       break;
 
-    case NEGATE_EXPR:
     case BIT_NOT_EXPR:
+      lhs = extract_affine (s, integer_minus_one_node, isl_space_copy (space));
+      rhs = extract_affine (s, TREE_OPERAND (e, 0), space);
+      res = isl_pw_aff_sub (lhs, rhs);
+      break;
+
+    case NEGATE_EXPR:
       lhs = extract_affine (s, TREE_OPERAND (e, 0), isl_space_copy (space));
       rhs = extract_affine (s, integer_minus_one_node, space);
       res = isl_pw_aff_mul (lhs, rhs);
@@ -279,6 +299,12 @@  extract_affine (scop_p s, tree e, __isl_
       return res;
 
     CASE_CONVERT:
+      res = extract_affine (s, TREE_OPERAND (e, 0), space);
+      /* signed values, even if overflow is undefined, get modulo-reduced.  */
+      if (! TYPE_UNSIGNED (type))
+	res = wrap (res, TYPE_PRECISION (type) - 1);
+      break;
+
     case NON_LVALUE_EXPR:
       res = extract_affine (s, TREE_OPERAND (e, 0), space);
       break;
@@ -288,7 +314,6 @@  extract_affine (scop_p s, tree e, __isl_
       break;
     }
 
-  tree type = TREE_TYPE (e);
   if (TYPE_UNSIGNED (type))
     res = wrap (res, TYPE_PRECISION (type));