diff mbox series

Punt on vectorizing sign-changing conditional reduction (PR tree-optimization/91665)

Message ID 20190907095634.GL2120@tucnak
State New
Headers show
Series Punt on vectorizing sign-changing conditional reduction (PR tree-optimization/91665) | expand

Commit Message

Jakub Jelinek Sept. 7, 2019, 9:56 a.m. UTC 
Hi!

We ICE on the following testcase, because we don't handle conditional
expression where base has incompatible type (the iv bumped in unsigned type,
but is signed otherwise, as happens for C/C++ signed char/short).
This patch just punts on it, during x86_64-linux and i686-linux
bootstrap/regtest it made a difference only on the testcase added by the
patch.

Preapproved by Richi on IRC, committed to trunk so far, queued for backporting.

2019-09-07  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/91665
	* tree-vect-loop.c (vectorizable_reduction): Punt if base has type
	incompatible with the type of PHI result.

	* gcc.dg/vect/pr91665.c: New test.


	Jakub
diff mbox series

Patch

--- gcc/tree-vect-loop.c.jj	2019-09-05 15:29:20.570627230 +0200
+++ gcc/tree-vect-loop.c	2019-09-06 19:39:18.777405377 +0200
@@ -6656,10 +6656,13 @@  vectorizable_reduction (stmt_vec_info st
 	  gcc_assert (TREE_CODE (base) == INTEGER_CST
 		      && TREE_CODE (step) == INTEGER_CST);
 	  cond_reduc_val = NULL_TREE;
+	  tree res = PHI_RESULT (STMT_VINFO_STMT (cond_stmt_vinfo));
+	  if (!types_compatible_p (TREE_TYPE (res), TREE_TYPE (base)))
+	    ;
 	  /* Find a suitable value, for MAX_EXPR below base, for MIN_EXPR
 	     above base; punt if base is the minimum value of the type for
 	     MAX_EXPR or maximum value of the type for MIN_EXPR for now.  */
-	  if (tree_int_cst_sgn (step) == -1)
+	  else if (tree_int_cst_sgn (step) == -1)
 	    {
 	      cond_reduc_op_code = MIN_EXPR;
 	      if (tree_int_cst_sgn (base) == -1)
--- gcc/testsuite/gcc.dg/vect/pr91665.c.jj	2019-09-05 14:20:01.986459651 +0200
+++ gcc/testsuite/gcc.dg/vect/pr91665.c	2019-09-05 13:54:52.944132072 +0200
@@ -0,0 +1,15 @@ 
+/* PR tree-optimization/91665 */
+/* { dg-do compile } */
+/* { dg-additional-options "-Ofast" } */
+
+short int v;
+
+void
+foo (short int x, short int y)
+{
+  short int *p = &v;
+
+  x = 1;
+  while (x != 0)
+    x += ++y || (*p = x);
+}