From: Richard Stallman <rms@gnu.org>
Date: Fri, 19 Feb 1993 05:46:22 +0000 (+0000)
Subject: (convert_to_integer): Warn if integer is truncated and that changes the value.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=4c42625bf5de7f1ae018bc45594ec7e39589af75;p=gcc.git

(convert_to_integer): Warn if integer is truncated and that changes the value.

From-SVN: r3496
---

diff --git a/gcc/convert.c b/gcc/convert.c
index c67f510188c..0833a5fbcd7 100644
--- a/gcc/convert.c
+++ b/gcc/convert.c
@@ -172,6 +172,30 @@ convert_to_integer (type, expr)
 
       switch (ex_form)
 	{
+        case INTEGER_CST:
+	  if (TREE_UNSIGNED (type))
+	    {
+	      if (TREE_INT_CST_LOW (expr) >> outprec)
+		warning ("integer constant truncated");
+	    }
+	  else
+	    {
+	      /* if the sign bit of the low-order part isn't replicated
+		 through the entire high part, we have overflow */
+	      int sign  = TREE_INT_CST_LOW (expr) & (1 << (outprec - 1));
+	      if (!sign)                       /* lower part positive */
+		{
+		  if (TREE_INT_CST_LOW (expr) >> outprec)
+		    warning ("integer constant truncated");
+		}
+	      else 
+		{
+		  if ((TREE_INT_CST_LOW (expr) >> outprec) + 1)
+		    warning ("integer constant truncated");
+		}
+	    }
+	  break;
+
 	case RSHIFT_EXPR:
 	  /* We can pass truncation down through right shifting
 	     when the shift count is a nonpositive constant.  */