optabs.c (emit_cmp_insn): Immediately copy the return value from the library call...

        * optabs.c (emit_cmp_insn): Immediately copy the return
        value from the library call into a pseudo register.
        (emit_float_lib_cmp): Likewise.

From-SVN: r11398

diff --git a/gcc/optabs.c b/gcc/optabs.c
index 4020e64ea050cf46279374f700f8d4b8a015d77a..09c4526ed9f2f8a754792240c792317fe3b24315 100644 (file)
--- a/gcc/optabs.c
+++ b/gcc/optabs.c
@@ -2743,6 +2743,8 @@ emit_cmp_insn (x, y, comparison, size, mode, unsignedp, align)
       else
 #endif
        {
+         rtx result;
+
 #ifdef TARGET_MEM_FUNCTIONS
          emit_library_call (memcmp_libfunc, 0,
                             TYPE_MODE (integer_type_node), 3,
@@ -2759,7 +2761,14 @@ emit_cmp_insn (x, y, comparison, size, mode, unsignedp, align)
                                              TREE_UNSIGNED (integer_type_node)),
                             TYPE_MODE (integer_type_node));
 #endif
-         emit_cmp_insn (hard_libcall_value (TYPE_MODE (integer_type_node)),
+
+         /* Immediately move the result of the libcall into a pseudo
+            register so reload doesn't clobber the value if it needs
+            the return register for a spill reg.  */
+         result = gen_reg_rtx (TYPE_MODE (integer_type_node));
+         emit_move_insn (result,
+                         hard_libcall_value (TYPE_MODE (integer_type_node)));
+         emit_cmp_insn (result,
                         const0_rtx, comparison, NULL_RTX,
                         TYPE_MODE (integer_type_node), 0, 0);
        }
@@ -2836,6 +2845,8 @@ emit_cmp_insn (x, y, comparison, size, mode, unsignedp, align)
       && class != MODE_FLOAT)
     {
       rtx libfunc = cmp_optab->handlers[(int) mode].libfunc;
+      rtx result;
+
       /* If we want unsigned, and this mode has a distinct unsigned
         comparison routine, use that.  */
       if (unsignedp && ucmp_optab->handlers[(int) mode].libfunc)
@@ -2844,11 +2855,16 @@ emit_cmp_insn (x, y, comparison, size, mode, unsignedp, align)
       emit_library_call (libfunc, 1,
                         word_mode, 2, x, mode, y, mode);
 
+      /* Immediately move the result of the libcall into a pseudo
+        register so reload doesn't clobber the value if it needs
+        the return register for a spill reg.  */
+      result = gen_reg_rtx (word_mode);
+      emit_move_insn (result, hard_libcall_value (word_mode));
+
       /* Integer comparison returns a result that must be compared against 1,
         so that even if we do an unsigned compare afterward,
         there is still a value that can represent the result "less than".  */
-
-      emit_cmp_insn (hard_libcall_value (word_mode), const1_rtx,
+      emit_cmp_insn (result, const1_rtx,
                     comparison, NULL_RTX, word_mode, unsignedp, 0);
       return;
     }
@@ -2887,6 +2903,7 @@ emit_float_lib_cmp (x, y, comparison)
 {
   enum machine_mode mode = GET_MODE (x);
   rtx libfunc = 0;
+  rtx result;
 
   if (mode == HFmode)
     switch (comparison)
@@ -3051,7 +3068,13 @@ emit_float_lib_cmp (x, y, comparison)
   emit_library_call (libfunc, 1,
                     word_mode, 2, x, mode, y, mode);
 
-  emit_cmp_insn (hard_libcall_value (word_mode), const0_rtx, comparison,
+  /* Immediately move the result of the libcall into a pseudo
+     register so reload doesn't clobber the value if it needs
+     the return register for a spill reg.  */
+  result = gen_reg_rtx (word_mode);
+  emit_move_insn (result, hard_libcall_value (word_mode));
+
+  emit_cmp_insn (result, const0_rtx, comparison,
                 NULL_RTX, word_mode, 0, 0);
 }
 \f