(gen_lowpart_common, gen_highpart, operand_subword): Don't make a new

REG for stack, frame, or arg pointer.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@2382 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
index d301bfc..f13d0d7 100644 (file)
--- a/gcc/emit-rtl.c
+++ b/gcc/emit-rtl.c
@@ -529,7 +529,14 @@ gen_lowpart_common (mode, x)
       else if (REGNO (x) < FIRST_PSEUDO_REGISTER
               /* integrate.c can't handle parts of a return value register. */
               && (! REG_FUNCTION_VALUE_P (x)
-                  || ! rtx_equal_function_value_matters))
+                  || ! rtx_equal_function_value_matters)
+              /* We want to keep the stack, frame, and arg pointers
+                 special.  */
+              && REGNO (x) != FRAME_POINTER_REGNUM
+#if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
+              && REGNO (x) != ARG_POINTER_REGNUM
+#endif
+              && REGNO (x) != STACK_POINTER_REGNUM)
        return gen_rtx (REG, mode, REGNO (x) + word);
       else
        return gen_rtx (SUBREG, mode, x, word);
@@ -776,7 +783,13 @@ gen_highpart (mode, x)
                 - MAX (GET_MODE_SIZE (mode), UNITS_PER_WORD))
                / UNITS_PER_WORD);
 #endif
-      if (REGNO (x) < FIRST_PSEUDO_REGISTER)
+      if (REGNO (x) < FIRST_PSEUDO_REGISTER
+         /* We want to keep the stack, frame, and arg pointers special.  */
+         && REGNO (x) != FRAME_POINTER_REGNUM
+#if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
+         && REGNO (x) != ARG_POINTER_REGNUM
+#endif
+         && REGNO (x) != STACK_POINTER_REGNUM)
        return gen_rtx (REG, mode, REGNO (x) + word);
       else
        return gen_rtx (SUBREG, mode, x, word);
@@ -860,7 +873,14 @@ operand_subword (op, i, validate_address, mode)
        return 0;
       else if (REGNO (op) >= FIRST_PSEUDO_REGISTER
               || (REG_FUNCTION_VALUE_P (op)
-                  && rtx_equal_function_value_matters))
+                  && rtx_equal_function_value_matters)
+              /* We want to keep the stack, frame, and arg pointers
+                 special.  */
+              || REGNO (op) == FRAME_POINTER_REGNUM
+#if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
+              || REGNO (op) == ARG_POINTER_REGNUM
+#endif
+              || REGNO (op) == STACK_POINTER_REGNUM)
        return gen_rtx (SUBREG, word_mode, op, i);
       else
        return gen_rtx (REG, word_mode, REGNO (op) + i);