(udivsi3): Don't clobber register 6.

(udivsi3, divsi3, mulsi3_call): Use a pseudo-reg with regclass 'z'
for output rather than hard register 0.
(block_move_real): Don't clobber registers 4 and 5.

From-SVN: r9224

diff --git a/gcc/config/sh/sh.md b/gcc/config/sh/sh.md
index df475e4ed91c0a99e5c09a87d301fa4e415e8f62..c17575d87443e1e69b516715ff024e8362f89087 100644 (file)
--- a/gcc/config/sh/sh.md
+++ b/gcc/config/sh/sh.md
@@ -292,17 +292,22 @@
 ;; Division instructions
 ;; -------------------------------------------------------------------------
 
-
 ;; we take advantage of the library routines which don't clobber as many
 ;; registers as a normal function call would.
 
+;; We must use a psuedo-reg forced to reg 0 in the SET_DEST rather than
+;; hard register 0.  If we used hard register 0, then the next instruction
+;; would be a move from hard register 0 to a pseudo-reg.  If the pseudo-reg
+;; gets allocated to a stack slot that needs its address reloaded, then
+;; there is nothing to prevent reload from using r0 to reload the address.
+;; This reload would clobber the value in r0 we are trying to store.
+;; If we let reload allocate r0, then this problem can never happen.
 
 (define_insn ""
-  [(set (reg:SI 0)
+  [(set (match_operand:SI 1 "register_operand" "=z")
        (udiv:SI (reg:SI 4) (reg:SI 5)))
    (clobber (reg:SI 18))
    (clobber (reg:SI 17))
-   (clobber (reg:SI 6))
    (clobber (reg:SI 4))
    (use (match_operand:SI 0 "arith_reg_operand" "r"))]
   ""
@@ -314,22 +319,18 @@
   [(set (reg:SI 4) (match_operand:SI 1 "general_operand" "g"))
    (set (reg:SI 5) (match_operand:SI 2 "general_operand" "g"))
    (set (match_dup 3) (symbol_ref:SI "__udivsi3"))
-   (parallel[(set (reg:SI 0)
+   (parallel[(set (match_operand:SI 0 "register_operand" "=z")
                  (udiv:SI (reg:SI 4)
                           (reg:SI 5)))
             (clobber (reg:SI 18))
             (clobber (reg:SI 17))
-            (clobber (reg:SI 6))
             (clobber (reg:SI 4))
-            (use (match_dup 3))])
-   (set (match_operand:SI 0 "general_operand" "=g")
-       (reg:SI 0))]
+            (use (match_dup 3))])]
   ""
   "operands[3] = gen_reg_rtx(SImode);")
 
-
 (define_insn ""
-  [(set (reg:SI 0)
+  [(set (match_operand:SI 1 "register_operand" "=z")
        (div:SI (reg:SI 4) (reg:SI 5)))
    (clobber (reg:SI 18))
    (clobber (reg:SI 17))
@@ -346,7 +347,7 @@
   [(set (reg:SI 4) (match_operand:SI 1 "general_operand" "g"))
    (set (reg:SI 5) (match_operand:SI 2 "general_operand" "g"))
    (set (match_dup 3) (symbol_ref:SI "__sdivsi3"))
-   (parallel[(set (reg:SI 0)
+   (parallel[(set (match_operand:SI 0 "register_operand" "=z")
                  (div:SI (reg:SI 4)
                           (reg:SI 5)))
             (clobber (reg:SI 18))
@@ -354,9 +355,7 @@
             (clobber (reg:SI 1))
             (clobber (reg:SI 2))
             (clobber (reg:SI 3))
-            (use (match_dup 3))])
-   (set (match_operand:SI 0 "general_operand" "=g")
-       (reg:SI 0))]
+            (use (match_dup 3))])]
   ""
   "operands[3] = gen_reg_rtx(SImode);")
 \f
@@ -408,7 +407,7 @@
 ;; a call to a routine which clobbers known registers.
 
 (define_insn ""
-  [(set (reg:SI 0)
+  [(set (match_operand:SI 1 "register_operand" "=z")
        (mult:SI (reg:SI 4) (reg:SI 5)))
    (clobber (reg:SI 21))
    (clobber (reg:SI 18))
@@ -426,7 +425,7 @@
   [(set (reg:SI 4) (match_operand:SI 1 "general_operand" "g"))
    (set (reg:SI 5) (match_operand:SI 2 "general_operand" "g"))
    (set (match_dup 3) (symbol_ref:SI "__mulsi3"))
-   (parallel[(set (reg:SI 0)
+   (parallel[(set (match_operand:SI 0 "register_operand" "=z")
                  (mult:SI (reg:SI 4)
                           (reg:SI 5)))
             (clobber (reg:SI 21))
@@ -435,9 +434,7 @@
             (clobber (reg:SI 3))
             (clobber (reg:SI 2))
             (clobber (reg:SI 1))
-            (use (match_dup 3))])
-   (set (match_operand:SI 0 "general_operand" "=g")
-       (reg:SI 0))]
+            (use (match_dup 3))])]
   ""
   "operands[3] = gen_reg_rtx(SImode);")
 
@@ -1675,8 +1672,6 @@
                   (mem:BLK (reg:SI 5)))
              (use (match_operand:SI 0 "arith_reg_operand" "r"))
              (clobber (reg:SI 17))
-             (clobber (reg:SI 4))
-             (clobber (reg:SI 5))
              (clobber (reg:SI 0))])]
   ""
   "jsr @%0%#"