re PR c/7102 (unsigned char divisision results in floating exception)

        PR c/7102
        * optabs.c (expand_binop): Convert CONST_INTs in all cases.

From-SVN: r56815

3 files changed, 31 insertions, 13 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7b8e319ab6f..ae3918f66d6 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2002-09-04  Eric Botcazou  <ebotcazou@multimania.com>
+
+	PR c/7102
+	* optabs.c (expand_binop): Convert CONST_INTs in all cases.
+
 2002-09-04  John David Anglin  <dave@hiauly1.hia.nrc.ca>
 
 	* pa.md (setccfp0, setccfp1): New patterns.
diff --git a/gcc/optabs.c b/gcc/optabs.c
index 3f17034f0d5..a7dae46dbcb 100644
--- a/gcc/optabs.c
+++ b/gcc/optabs.c
@@ -779,23 +779,18 @@ expand_binop (mode, binoptab, op0, op1, target, unsignedp, methods)
 	}
 
       /* In case the insn wants input operands in modes different from
-	 the result, convert the operands.  It would seem that we
-	 don't need to convert CONST_INTs, but we do, so that they're
-	 a properly sign-extended for their modes; we choose the
-	 widest mode between mode and mode[01], so that, in a widening
-	 operation, we call convert_modes with different FROM and TO
-	 modes, which ensures the value is sign-extended.  Shift
-	 operations are an exception, because the second operand needs
-	 not be extended to the mode of the result.  */
+	 those of the actual operands, convert the operands.  It would
+	 seem that we don't need to convert CONST_INTs, but we do, so
+	 that they're properly zero-extended or sign-extended for their
+	 modes; shift operations are an exception, because the second
+	 operand needs not be extended to the mode of the result.  */
 
       if (GET_MODE (op0) != mode0
 	  && mode0 != VOIDmode)
 	xop0 = convert_modes (mode0,
 			      GET_MODE (op0) != VOIDmode
 			      ? GET_MODE (op0)
-			      : GET_MODE_SIZE (mode) > GET_MODE_SIZE (mode0)
-			      ? mode
-			      : mode0,
+			      : mode,
 			      xop0, unsignedp);
 
       if (GET_MODE (xop1) != mode1
@@ -803,8 +798,7 @@ expand_binop (mode, binoptab, op0, op1, target, unsignedp, methods)
 	xop1 = convert_modes (mode1,
 			      GET_MODE (op1) != VOIDmode
 			      ? GET_MODE (op1)
-			      : (GET_MODE_SIZE (mode) > GET_MODE_SIZE (mode1)
-				 && ! shift_op)
+			      : ! shift_op
 			      ? mode
 			      : mode1,
 			      xop1, unsignedp);
diff --git a/gcc/testsuite/gcc.c-torture/execute/20020904-1.c b/gcc/testsuite/gcc.c-torture/execute/20020904-1.c
new file mode 100644
index 00000000000..24eeb0cb0a0
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/20020904-1.c
@@ -0,0 +1,19 @@
+/* PR c/7102 */
+
+/* Verify that GCC zero-extends integer constants
+   in unsigned binary operations. */
+
+typedef unsigned char u8;
+
+u8 fun(u8 y)
+{
+  u8 x=((u8)255)/y;
+  return x;
+}
+
+int main(void)
+{
+  if (fun((u8)2) != 127)
+    abort ();
+  return 0;
+}