re PR inline-asm/8832 (traditional "asm volatile" code is illegally optimized)

	PR inline-asm/8832
	* tree.h (expand_asm): New prototype.
	* stmt.c (expand_asm): Set the MEM_VOLATILE_P flag if instructed
	to do so.
	* c-semantics (genrtl_asm_stmt): Pass the RID_VOLATILE qualifier
	down to expand_asm.
	* c-typeck.c (simple_asm_stmt): Set the RID_VOLATILE qualifier.
	* rtlanal.c (volatile_insn_p) [ASM_INPUT]: Test the MEM_VOLATILE_P flag.
	(volatile_refs_p) [ASM_INPUT]: Likewise.
	(side_effects_p) [ASM_INPUT]: Likewise.

From-SVN: r61099

gcc/ChangeLog

+2003-01-09  Eric Botcazou  <ebotcazou@libertysurf.fr>
+
+	PR inline-asm/8832
+	* tree.h (expand_asm): New prototype.
+	* stmt.c (expand_asm): Set the MEM_VOLATILE_P flag if instructed
+	to do so.
+	* c-semantics (genrtl_asm_stmt): Pass the RID_VOLATILE qualifier
+	down to expand_asm.
+	* c-typeck.c (simple_asm_stmt): Set the RID_VOLATILE qualifier.
+	* rtlanal.c (volatile_insn_p) [ASM_INPUT]: Test the MEM_VOLATILE_P flag.
+	(volatile_refs_p) [ASM_INPUT]: Likewise.
+	(side_effects_p) [ASM_INPUT]: Likewise.
+
 Thu Jan  9 12:00:36 CET 2003  Jan Hubicka  <jh@suse.cz>
 
 	* i386.md (*mul*): FIx constraints; remove confused comment; fix

gcc/c-semantics.c

@@ -749,7 +749,7 @@ genrtl_asm_stmt (cv_qualifier, string, output_operands,
 
   emit_line_note (input_filename, lineno);
   if (asm_input_p)
-    expand_asm (string);
+    expand_asm (string, cv_qualifier != NULL_TREE);
   else
     c_expand_asm_operands (string, output_operands, input_operands, 
 			   clobbers, cv_qualifier != NULL_TREE,

gcc/c-typeck.c

@@ -6853,9 +6853,9 @@ simple_asm_stmt (expr)
     {
       tree stmt;
 
-      stmt = add_stmt (build_stmt (ASM_STMT, NULL_TREE, expr,
-				   NULL_TREE, NULL_TREE,
-				   NULL_TREE));
+      /* Simple asm statements are treated as volatile.  */
+      stmt = add_stmt (build_stmt (ASM_STMT, ridpointers[(int) RID_VOLATILE],
+				   expr, NULL_TREE, NULL_TREE, NULL_TREE));
       ASM_INPUT_P (stmt) = 1;
       return stmt;
     }

gcc/rtlanal.c

@@ -2237,7 +2237,6 @@ volatile_insn_p (x)
     case REG:
     case SCRATCH:
     case CLOBBER:
-    case ASM_INPUT:
     case ADDR_VEC:
     case ADDR_DIFF_VEC:
     case CALL:
@@ -2248,6 +2247,7 @@ volatile_insn_p (x)
  /* case TRAP_IF: This isn't clear yet.  */
       return 1;
 
+    case ASM_INPUT:
     case ASM_OPERANDS:
       if (MEM_VOLATILE_P (x))
 	return 1;
@@ -2304,7 +2304,6 @@ volatile_refs_p (x)
     case REG:
     case SCRATCH:
     case CLOBBER:
-    case ASM_INPUT:
     case ADDR_VEC:
     case ADDR_DIFF_VEC:
       return 0;
@@ -2313,6 +2312,7 @@ volatile_refs_p (x)
       return 1;
 
     case MEM:
+    case ASM_INPUT:
     case ASM_OPERANDS:
       if (MEM_VOLATILE_P (x))
 	return 1;
@@ -2368,7 +2368,6 @@ side_effects_p (x)
     case PC:
     case REG:
     case SCRATCH:
-    case ASM_INPUT:
     case ADDR_VEC:
     case ADDR_DIFF_VEC:
       return 0;
@@ -2391,6 +2390,7 @@ side_effects_p (x)
       return 1;
 
     case MEM:
+    case ASM_INPUT:
     case ASM_OPERANDS:
       if (MEM_VOLATILE_P (x))
 	return 1;

gcc/stmt.c

@@ -1098,18 +1098,26 @@ n_occurrences (c, s)
 }
 
 /* Generate RTL for an asm statement (explicit assembler code).
-   BODY is a STRING_CST node containing the assembler code text,
-   or an ADDR_EXPR containing a STRING_CST.  */
+   STRING is a STRING_CST node containing the assembler code text,
+   or an ADDR_EXPR containing a STRING_CST.  VOL nonzero means the
+   insn is volatile; don't optimize it.  */
 
 void
-expand_asm (body)
-     tree body;
+expand_asm (string, vol)
+     tree string;
+     int vol;
 {
-  if (TREE_CODE (body) == ADDR_EXPR)
-    body = TREE_OPERAND (body, 0);
+  rtx body;
+
+  if (TREE_CODE (string) == ADDR_EXPR)
+    string = TREE_OPERAND (string, 0);
+
+  body = gen_rtx_ASM_INPUT (VOIDmode, TREE_STRING_POINTER (string));
+
+  MEM_VOLATILE_P (body) = vol;
 
-  emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
-				TREE_STRING_POINTER (body)));
+  emit_insn (body);
+  
   clear_last_expr ();
 }
 

gcc/testsuite/ChangeLog

+2003-01-09  Eric Botcazou  <ebotcazou@libertysurf.fr>
+
+	gcc.dg/old-style-asm-1.c: New test.
+
 2003-01-09  Richard Sandiford  <rsandifo@redhat.com>
 
 	* gcc.c-torture/compile/20030109-1.c: New test.

gcc/testsuite/gcc.dg/old-style-asm-1.c

+/* PR inline-asm/8832 */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+/* Verify that GCC doesn't optimize
+   old style asm instructions.  */
+
+void foo(int v)
+{
+  if (v)
+    asm ("dummy1");
+
+  asm ("dummy2");
+
+  if (v)
+    asm ("dummy3");
+}
+
+/* { dg-final { scan-assembler "L2" } } */

gcc/tree.h

@@ -2835,7 +2835,7 @@ extern void expand_decl_init			PARAMS ((tree));
 extern void clear_last_expr			PARAMS ((void));
 extern void expand_label			PARAMS ((tree));
 extern void expand_goto				PARAMS ((tree));
-extern void expand_asm				PARAMS ((tree));
+extern void expand_asm				PARAMS ((tree, int));
 extern void expand_start_cond			PARAMS ((tree, int));
 extern void expand_end_cond			PARAMS ((void));
 extern void expand_start_else			PARAMS ((void));