builtins.c (expand_builtin_strcmp): Defend against the possibility that gen_cmpstrsi may fail...

	* builtins.c (expand_builtin_strcmp): Defend against the possibility
	that gen_cmpstrsi may fail: Stabilize the argument list against
	re-evaluation and expand the library call directly using this saved
	argument list if a cmpstrsi sequence can't be generated.
	(expand_builtin_strncmp): Likewise.

	* config/i386/i386.md (cmpstrsi, movstrsi): Disable with -Os.

	* gcc.c-torture/execute/string-opt-8.c: Don't test optimizations
	that inline strncmp as cmpstrsi on i386 when compiled with -Os.

From-SVN: r72380

5 files changed, 70 insertions, 27 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4251bf3..a05b726 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,15 @@
 2003-10-11  Roger Sayle  <roger@eyesopen.com>
 
+	* builtins.c (expand_builtin_strcmp): Defend against the possibility
+	that gen_cmpstrsi may fail: Stabilize the argument list against
+	re-evaluation and expand the library call directly using this saved
+	argument list if a cmpstrsi sequence can't be generated.
+	(expand_builtin_strncmp): Likewise.
+
+	* config/i386/i386.md (cmpstrsi, movstrsi): Disable with -Os.
+
+2003-10-11  Roger Sayle  <roger@eyesopen.com>
+
 	PR optimization/12260
 	* simplify-rtx.c (simplify_unary_operation): Simplify all unary
 	operations through CONST nodes.  Optimize (neg (plus X C)) as
diff --git a/gcc/builtins.c b/gcc/builtins.c
index 1af2a2d..0214edf 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -3281,6 +3281,7 @@ expand_builtin_strcmp (tree exp, rtx target, enum machine_mode mode)
     tree len, len1, len2;
     rtx arg1_rtx, arg2_rtx, arg3_rtx;
     rtx result, insn;
+    tree fndecl;
 
     int arg1_align
       = get_pointer_alignment (arg1, BIGGEST_ALIGNMENT) / BITS_PER_UNIT;
@@ -3336,24 +3337,36 @@ expand_builtin_strcmp (tree exp, rtx target, enum machine_mode mode)
 	   && REGNO (result) >= FIRST_PSEUDO_REGISTER))
       result = gen_reg_rtx (insn_mode);
 
+    /* Stabilize the arguments in case gen_cmpstrsi fails.  */
+    arg1 = save_expr (arg1);
+    arg2 = save_expr (arg2);
+
     arg1_rtx = get_memory_rtx (arg1);
     arg2_rtx = get_memory_rtx (arg2);
     arg3_rtx = expand_expr (len, NULL_RTX, VOIDmode, 0);
     insn = gen_cmpstrsi (result, arg1_rtx, arg2_rtx, arg3_rtx,
 			 GEN_INT (MIN (arg1_align, arg2_align)));
-    if (!insn)
-      return 0;
-
-    emit_insn (insn);
+    if (insn)
+      {
+	emit_insn (insn);
+
+	/* Return the value in the proper mode for this function.  */
+	mode = TYPE_MODE (TREE_TYPE (exp));
+	if (GET_MODE (result) == mode)
+	  return result;
+	if (target == 0)
+	  return convert_to_mode (mode, result, 0);
+	convert_move (target, result, 0);
+	return target;
+      }
 
-    /* Return the value in the proper mode for this function.  */
-    mode = TYPE_MODE (TREE_TYPE (exp));
-    if (GET_MODE (result) == mode)
-      return result;
-    if (target == 0)
-      return convert_to_mode (mode, result, 0);
-    convert_move (target, result, 0);
-    return target;
+    /* Expand the library call ourselves using a stabilized argument
+       list to avoid re-evaluating the function's arguments twice.  */
+    arglist = build_tree_list (NULL_TREE, arg2);
+    arglist = tree_cons (NULL_TREE, arg1, arglist);
+    fndecl = get_callee_fndecl (exp);
+    exp = build_function_call_expr (fndecl, arglist);
+    return expand_call (exp, target, target == const0_rtx);
   }
 #endif
   return 0;
@@ -3436,6 +3449,7 @@ expand_builtin_strncmp (tree exp, rtx target, enum machine_mode mode)
     tree len, len1, len2;
     rtx arg1_rtx, arg2_rtx, arg3_rtx;
     rtx result, insn;
+    tree fndecl;
 
     int arg1_align
       = get_pointer_alignment (arg1, BIGGEST_ALIGNMENT) / BITS_PER_UNIT;
@@ -3494,24 +3508,38 @@ expand_builtin_strncmp (tree exp, rtx target, enum machine_mode mode)
 	   && REGNO (result) >= FIRST_PSEUDO_REGISTER))
       result = gen_reg_rtx (insn_mode);
 
+    /* Stabilize the arguments in case gen_cmpstrsi fails.  */
+    arg1 = save_expr (arg1);
+    arg2 = save_expr (arg2);
+    len = save_expr (len);
+
     arg1_rtx = get_memory_rtx (arg1);
     arg2_rtx = get_memory_rtx (arg2);
     arg3_rtx = expand_expr (len, NULL_RTX, VOIDmode, 0);
     insn = gen_cmpstrsi (result, arg1_rtx, arg2_rtx, arg3_rtx,
 			 GEN_INT (MIN (arg1_align, arg2_align)));
-    if (!insn)
-      return 0;
-
-    emit_insn (insn);
+    if (insn)
+      {
+	emit_insn (insn);
+
+	/* Return the value in the proper mode for this function.  */
+	mode = TYPE_MODE (TREE_TYPE (exp));
+	if (GET_MODE (result) == mode)
+	  return result;
+	if (target == 0)
+	  return convert_to_mode (mode, result, 0);
+	convert_move (target, result, 0);
+	return target;
+      }
 
-    /* Return the value in the proper mode for this function.  */
-    mode = TYPE_MODE (TREE_TYPE (exp));
-    if (GET_MODE (result) == mode)
-      return result;
-    if (target == 0)
-      return convert_to_mode (mode, result, 0);
-    convert_move (target, result, 0);
-    return target;
+    /* Expand the library call ourselves using a stabilized argument
+       list to avoid re-evaluating the function's arguments twice.  */
+    arglist = build_tree_list (NULL_TREE, len);
+    arglist = tree_cons (NULL_TREE, arg2, arglist);
+    arglist = tree_cons (NULL_TREE, arg1, arglist);
+    fndecl = get_callee_fndecl (exp);
+    exp = build_function_call_expr (fndecl, arglist);
+    return expand_call (exp, target, target == const0_rtx);
   }
 #endif
   return 0;
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index a1f40e1..39a8a2c 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -16129,7 +16129,7 @@
    (use (match_operand:BLK 1 "memory_operand" ""))
    (use (match_operand:SI 2 "nonmemory_operand" ""))
    (use (match_operand:SI 3 "const_int_operand" ""))]
-  ""
+  "! optimize_size"
 {
  if (ix86_expand_movstr (operands[0], operands[1], operands[2], operands[3]))
    DONE;
@@ -16849,7 +16849,7 @@
 		    (match_operand:BLK 2 "general_operand" "")))
    (use (match_operand 3 "general_operand" ""))
    (use (match_operand 4 "immediate_operand" ""))]
-  ""
+  "! optimize_size"
 {
   rtx addr1, addr2, out, outlow, count, countreg, align;
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ad9bafc..92b96a2 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,10 @@
 2003-10-11  Roger Sayle  <roger@eyesopen.com>
 
+	* gcc.c-torture/execute/string-opt-8.c: Don't test optimizations
+	that inline strncmp as cmpstrsi on i386 when compiled with -Os.
+
+2003-10-11  Roger Sayle  <roger@eyesopen.com>
+
 	PR optimization/12260
 	* gcc.c-torture/compile/20031011-2.c: New test case.
 
diff --git a/gcc/testsuite/gcc.c-torture/execute/string-opt-8.c b/gcc/testsuite/gcc.c-torture/execute/string-opt-8.c
index 434de33..2316fce 100644
--- a/gcc/testsuite/gcc.c-torture/execute/string-opt-8.c
+++ b/gcc/testsuite/gcc.c-torture/execute/string-opt-8.c
@@ -65,7 +65,7 @@ int main ()
   s2 = s1; s3 = s1+4;
   if (strncmp (++s2, ++s3+2, 1) >= 0 || s2 != s1+1 || s3 != s1+5)
     abort();
-#if !defined(__OPTIMIZE__) || defined(__i386__)
+#if !defined(__OPTIMIZE__) || (defined(__i386__) && !defined(__OPTIMIZE_SIZE__))
   /* These tests work on platforms which support cmpstrsi.  We test it
      at -O0 on all platforms to ensure the strncmp logic is correct.  */
   s2 = s1;