re PR target/36613 (likely codegen bug)

        PR target/36613

        * reload.c (push_reload): Merge in,out,in_reg,out_reg members
        for reused reload, instead of overwriting them.

        * gcc.target/i386/pr36613.c: New testcase.

From-SVN: r138807

4 files changed, 82 insertions, 4 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a22491f..a08bd6e 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2008-08-06  Michael Matz  <matz@suse.de>
+
+	PR target/36613
+	* reload.c (push_reload): Merge in,out,in_reg,out_reg members
+	for reused reload, instead of overwriting them.
+
 2008-08-06  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR middle-end/37009
diff --git a/gcc/reload.c b/gcc/reload.c
index 93fff404..5a79c44 100644
--- a/gcc/reload.c
+++ b/gcc/reload.c
@@ -1403,13 +1403,36 @@ push_reload (rtx in, rtx out, rtx *inloc, rtx *outloc,
 	      else
 		remove_address_replacements (rld[i].in);
 	    }
-	  rld[i].in = in;
-	  rld[i].in_reg = in_reg;
+	  /* When emitting reloads we don't necessarily look at the in-
+	     and outmode, but also directly at the operands (in and out).
+	     So we can't simply overwrite them with whatever we have found
+	     for this (to-be-merged) reload, we have to "merge" that too.
+	     Reusing another reload already verified that we deal with the
+	     same operands, just possibly in different modes.  So we
+	     overwrite the operands only when the new mode is larger.
+	     See also PR33613.  */
+	  if (!rld[i].in
+	      || GET_MODE_SIZE (GET_MODE (in))
+	           > GET_MODE_SIZE (GET_MODE (rld[i].in)))
+	    rld[i].in = in;
+	  if (!rld[i].in_reg
+	      || (in_reg
+		  && GET_MODE_SIZE (GET_MODE (in_reg))
+	             > GET_MODE_SIZE (GET_MODE (rld[i].in_reg))))
+	    rld[i].in_reg = in_reg;
 	}
       if (out != 0)
 	{
-	  rld[i].out = out;
-	  rld[i].out_reg = outloc ? *outloc : 0;
+	  if (!rld[i].out
+	      || (out
+		  && GET_MODE_SIZE (GET_MODE (out))
+	             > GET_MODE_SIZE (GET_MODE (rld[i].out))))
+	    rld[i].out = out;
+	  if (outloc
+	      && (!rld[i].out_reg
+		  || GET_MODE_SIZE (GET_MODE (*outloc))
+		     > GET_MODE_SIZE (GET_MODE (rld[i].out_reg))))
+	    rld[i].out_reg = *outloc;
 	}
       if (reg_class_subset_p (rclass, rld[i].rclass))
 	rld[i].rclass = rclass;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ead9638..d5b229a 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2008-08-06  Michael Matz  <matz@suse.de>
+
+	PR target/36613
+	* gcc.target/i386/pr36613.c: New testcase.
+
 2008-08-06  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR middle-end/37009
diff --git a/gcc/testsuite/gcc.target/i386/pr36613.c b/gcc/testsuite/gcc.target/i386/pr36613.c
new file mode 100644
index 0000000..e9d7d11
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr36613.c
@@ -0,0 +1,44 @@
+/* { dg-do run { target { { i?86-*-linux* x86_64-*-linux* } && ilp32 } } } */
+/* { dg-options "-Os" } */
+/* PR target/36613 */
+
+extern void abort (void);
+
+static inline int
+lshifts (int val, int cnt)
+{
+  if (val < 0)
+    return val;
+  return val << cnt;
+}
+
+static inline unsigned int
+lshiftu (unsigned int val, unsigned int cnt)
+{
+  if (cnt >= sizeof (unsigned int) * __CHAR_BIT__
+      || val > ((__INT_MAX__ * 2U) >> cnt))
+    return val;
+  return val << cnt;
+}
+
+static inline int
+rshifts (int val, unsigned int cnt)
+{
+  if (val < 0 || cnt >= sizeof (int) * __CHAR_BIT__)
+    return val;
+  return val >> cnt;
+}
+
+int
+foo (unsigned int val)
+{
+  return rshifts (1 + val, lshifts (lshiftu (val, val), 1));
+}
+
+int
+main (void)
+{
+  if (foo (1) != 0)
+    abort ();
+  return 0;
+}