reg-stack.c (swap_to_top): New function.

2004-04-23  Uros Bizjak  <uros@kss-loka.si>

        * reg-stack.c (swap_to_top): New function.
        (subst_stack_regs_pat): UNSPEC_FPATAN, UNSPEC_FYL2X: Use\
        swap_to_top().
        (subst_stack_regs_pat): UNSPEC_FSCALE: Remove.
        (subst_stack_regs_pat): Handle UNSPEC_FSCALE_FRACT and
        UNSPEC_FSCALE_EXP.

        * config/i386/i386.md (UNSPEC_FSCALE): Remove.
        (*fscale_sfxf3, *fscale_dfxf3, *fscale_xf3): Remove insn pattern.
        (UNSPEC_FSCALE_FRACT, UNSPEC_FSCALE_EXP): New unspecs to represent
        x87's fscale insn.
        (*fscalexf4: Define new insn pattern to implement x87 fscale insn.
        (exp?f2, exp10?f2, exp2?f2): Use *fscalexf4 and float_truncate
        patterns.

From-SVN: r81278

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f6c618edfb9acb63d3de05aed44cc4f2f983f260..3916f83518c285fb9baa8c63f03cf9dae1e923e2 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,20 @@
+2004-04-29  Uros Bizjak  <uros@kss-loka.si>
+
+        * reg-stack.c (swap_to_top): New function.
+        (subst_stack_regs_pat): UNSPEC_FPATAN, UNSPEC_FYL2X: Use
+        swap_to_top().
+        (subst_stack_regs_pat): UNSPEC_FSCALE: Remove.
+        (subst_stack_regs_pat): Handle UNSPEC_FSCALE_FRACT and 
+        UNSPEC_FSCALE_EXP.
+
+        * config/i386/i386.md (UNSPEC_FSCALE): Remove.
+        (*fscale_sfxf3, *fscale_dfxf3, *fscale_xf3): Remove insn pattern.
+        (UNSPEC_FSCALE_FRACT, UNSPEC_FSCALE_EXP): New unspecs to represent
+        x87's fscale insn.
+        (*fscalexf4: Define new insn pattern to implement x87 fscale insn.
+        (exp?f2, exp10?f2, exp2?f2): Use *fscalexf4 and float_truncate
+        patterns.
+
 2004-04-28  Serge Belyshev  <1319@bot.ru>
 
        PR 14944

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index c0a3ff4cfe5baa757178eda893c690e7548f52e6..fbb39c1cd7afe8fe0f42de90ae34fd584dd9f431 100644 (file)
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -117,7 +117,6 @@
    ; x87 Floating point
    (UNSPEC_FPATAN              65)
    (UNSPEC_FYL2X               66)
-   (UNSPEC_FSCALE              67)
    (UNSPEC_FRNDINT             68)
    (UNSPEC_F2XM1               69)
 
@@ -128,6 +127,8 @@
    (UNSPEC_TAN_TAN             83)
    (UNSPEC_XTRACT_FRACT                84)
    (UNSPEC_XTRACT_EXP          85)
+   (UNSPEC_FSCALE_FRACT                86)
+   (UNSPEC_FSCALE_EXP          87)
 
    ; REP instruction
    (UNSPEC_REP                 75)
@@ -15669,42 +15670,6 @@
   operands[3] = gen_reg_rtx (XFmode);
 })
 
-(define_insn "*fscale_sfxf3"
-  [(set (match_operand:SF 0 "register_operand" "=f")
-        (unspec:SF [(match_operand:XF 2 "register_operand" "0")
-                    (match_operand:XF 1 "register_operand" "u")]
-                   UNSPEC_FSCALE))
-   (clobber (match_scratch:SF 3 "=1"))]
-  "! TARGET_NO_FANCY_MATH_387 && TARGET_80387
-   && flag_unsafe_math_optimizations"
-  "fscale\;fstp\t%y1"
-  [(set_attr "type" "fpspc")
-   (set_attr "mode" "SF")])
-
-(define_insn "*fscale_dfxf3"
-  [(set (match_operand:DF 0 "register_operand" "=f")
-        (unspec:DF [(match_operand:XF 2 "register_operand" "0")
-                    (match_operand:XF 1 "register_operand" "u")]
-                   UNSPEC_FSCALE))
-   (clobber (match_scratch:DF 3 "=1"))]
-  "! TARGET_NO_FANCY_MATH_387 && TARGET_80387
-   && flag_unsafe_math_optimizations"
-  "fscale\;fstp\t%y1"
-  [(set_attr "type" "fpspc")
-   (set_attr "mode" "DF")])
-
-(define_insn "*fscale_xf3"
-  [(set (match_operand:XF 0 "register_operand" "=f")
-       (unspec:XF [(match_operand:XF 2 "register_operand" "0")
-                   (match_operand:XF 1 "register_operand" "u")]
-                  UNSPEC_FSCALE))
-   (clobber (match_scratch:XF 3 "=1"))]
-  "! TARGET_NO_FANCY_MATH_387 && TARGET_80387
-   && flag_unsafe_math_optimizations"
-  "fscale\;fstp\t%y1"
-  [(set_attr "type" "fpspc")
-   (set_attr "mode" "XF")])
-
 (define_insn "*frndintxf2"
   [(set (match_operand:XF 0 "register_operand" "=f")
        (unspec:XF [(match_operand:XF 1 "register_operand" "0")]
@@ -15725,6 +15690,20 @@
   [(set_attr "type" "fpspc")
    (set_attr "mode" "XF")])
 
+(define_insn "*fscalexf4"
+  [(set (match_operand:XF 0 "register_operand" "=f")
+       (unspec:XF [(match_operand:XF 2 "register_operand" "0")
+                   (match_operand:XF 3 "register_operand" "1")]
+                  UNSPEC_FSCALE_FRACT))
+   (set (match_operand:XF 1 "register_operand" "=u")
+       (unspec:XF [(match_dup 2) (match_dup 3)]
+                  UNSPEC_FSCALE_EXP))]
+  "! TARGET_NO_FANCY_MATH_387 && TARGET_80387 
+   && flag_unsafe_math_optimizations"
+  "fscale"
+  [(set_attr "type" "fpspc")
+   (set_attr "mode" "DF")])
+
 (define_expand "expsf2"
   [(set (match_dup 2)
        (float_extend:XF (match_operand:SF 1 "register_operand" "")))
@@ -15733,16 +15712,21 @@
    (set (match_dup 6) (minus:XF (match_dup 4) (match_dup 5)))
    (set (match_dup 7) (unspec:XF [(match_dup 6)] UNSPEC_F2XM1))
    (set (match_dup 9) (plus:XF (match_dup 7) (match_dup 8)))
-   (parallel [(set (match_operand:SF 0 "register_operand" "")
-                  (unspec:SF [(match_dup 9) (match_dup 5)] UNSPEC_FSCALE))
-             (clobber (match_scratch:SF 5 ""))])]
+   (parallel [(set (match_dup 10)
+                  (unspec:XF [(match_dup 9) (match_dup 5)]
+                             UNSPEC_FSCALE_FRACT))
+             (set (match_dup 11)
+                  (unspec:XF [(match_dup 9) (match_dup 5)]
+                             UNSPEC_FSCALE_EXP))])
+   (set (match_operand:SF 0 "register_operand" "")
+       (float_truncate:SF (match_dup 10)))]
   "! TARGET_NO_FANCY_MATH_387 && TARGET_80387
    && flag_unsafe_math_optimizations"
 {
   rtx temp;
   int i;
 
-  for (i=2; i<10; i++)
+  for (i=2; i<12; i++)
     operands[i] = gen_reg_rtx (XFmode);
   temp = standard_80387_constant_rtx (5); /* fldl2e */
   emit_move_insn (operands[3], temp);
@@ -15755,19 +15739,23 @@
    (set (match_dup 4) (mult:XF (match_dup 2) (match_dup 3)))
    (set (match_dup 5) (unspec:XF [(match_dup 4)] UNSPEC_FRNDINT))
    (set (match_dup 6) (minus:XF (match_dup 4) (match_dup 5)))
-
    (set (match_dup 7) (unspec:XF [(match_dup 6)] UNSPEC_F2XM1))
    (set (match_dup 9) (plus:XF (match_dup 7) (match_dup 8)))
-   (parallel [(set (match_operand:DF 0 "register_operand" "")
-                  (unspec:DF [(match_dup 9) (match_dup 5)] UNSPEC_FSCALE))
-             (clobber (match_scratch:DF 5 ""))])]
+   (parallel [(set (match_dup 10)
+                  (unspec:XF [(match_dup 9) (match_dup 5)]
+                             UNSPEC_FSCALE_FRACT))
+             (set (match_dup 11)
+                  (unspec:XF [(match_dup 9) (match_dup 5)]
+                             UNSPEC_FSCALE_EXP))])
+   (set (match_operand:DF 0 "register_operand" "")
+       (float_truncate:DF (match_dup 10)))]
   "! TARGET_NO_FANCY_MATH_387 && TARGET_80387
    && flag_unsafe_math_optimizations"
 {
   rtx temp;
   int i;
 
-  for (i=2; i<10; i++)
+  for (i=2; i<12; i++)
     operands[i] = gen_reg_rtx (XFmode);
   temp = standard_80387_constant_rtx (5); /* fldl2e */
   emit_move_insn (operands[3], temp);
@@ -15782,15 +15770,18 @@
    (set (match_dup 6) (unspec:XF [(match_dup 5)] UNSPEC_F2XM1))
    (set (match_dup 8) (plus:XF (match_dup 6) (match_dup 7)))
    (parallel [(set (match_operand:XF 0 "register_operand" "")
-                  (unspec:XF [(match_dup 8) (match_dup 4)] UNSPEC_FSCALE))
-             (clobber (match_scratch:XF 5 ""))])]
+                  (unspec:XF [(match_dup 8) (match_dup 4)]
+                             UNSPEC_FSCALE_FRACT))
+             (set (match_dup 9)
+                  (unspec:XF [(match_dup 8) (match_dup 4)]
+                             UNSPEC_FSCALE_EXP))])]
   "! TARGET_NO_FANCY_MATH_387 && TARGET_80387
    && flag_unsafe_math_optimizations"
 {
   rtx temp;
   int i;
 
-  for (i=2; i<9; i++)
+  for (i=2; i<10; i++)
     operands[i] = gen_reg_rtx (XFmode);
   temp = standard_80387_constant_rtx (5); /* fldl2e */
   emit_move_insn (operands[2], temp);
@@ -15805,16 +15796,21 @@
    (set (match_dup 6) (minus:XF (match_dup 4) (match_dup 5)))
    (set (match_dup 7) (unspec:XF [(match_dup 6)] UNSPEC_F2XM1))
    (set (match_dup 9) (plus:XF (match_dup 7) (match_dup 8)))
-   (parallel [(set (match_operand:SF 0 "register_operand" "")
-                  (unspec:SF [(match_dup 9) (match_dup 5)] UNSPEC_FSCALE))
-             (clobber (match_scratch:SF 5 ""))])]
+   (parallel [(set (match_dup 10)
+                  (unspec:XF [(match_dup 9) (match_dup 5)]
+                             UNSPEC_FSCALE_FRACT))
+             (set (match_dup 11)
+                  (unspec:XF [(match_dup 9) (match_dup 5)]
+                             UNSPEC_FSCALE_EXP))])
+   (set (match_operand:SF 0 "register_operand" "")
+       (float_truncate:SF (match_dup 10)))]
   "! TARGET_NO_FANCY_MATH_387 && TARGET_80387
    && flag_unsafe_math_optimizations"
 {
   rtx temp;
   int i;
 
-  for (i=2; i<10; i++)
+  for (i=2; i<12; i++)
     operands[i] = gen_reg_rtx (XFmode);
   temp = standard_80387_constant_rtx (6); /* fldl2t */
   emit_move_insn (operands[3], temp);
@@ -15829,16 +15825,21 @@
    (set (match_dup 6) (minus:XF (match_dup 4) (match_dup 5)))
    (set (match_dup 7) (unspec:XF [(match_dup 6)] UNSPEC_F2XM1))
    (set (match_dup 9) (plus:XF (match_dup 7) (match_dup 8)))
-   (parallel [(set (match_operand:DF 0 "register_operand" "")
-                  (unspec:DF [(match_dup 9) (match_dup 5)] UNSPEC_FSCALE))
-             (clobber (match_scratch:DF 5 ""))])]
+   (parallel [(set (match_dup 10)
+                  (unspec:XF [(match_dup 9) (match_dup 5)]
+                             UNSPEC_FSCALE_FRACT))
+             (set (match_dup 11)
+                  (unspec:XF [(match_dup 9) (match_dup 5)]
+                             UNSPEC_FSCALE_EXP))])
+   (set (match_operand:DF 0 "register_operand" "")
+       (float_truncate:DF (match_dup 10)))]
   "! TARGET_NO_FANCY_MATH_387 && TARGET_80387
    && flag_unsafe_math_optimizations"
 {
   rtx temp;
   int i;
 
-  for (i=2; i<10; i++)
+  for (i=2; i<12; i++)
     operands[i] = gen_reg_rtx (XFmode);
   temp = standard_80387_constant_rtx (6); /* fldl2t */
   emit_move_insn (operands[3], temp);
@@ -15853,15 +15854,18 @@
    (set (match_dup 6) (unspec:XF [(match_dup 5)] UNSPEC_F2XM1))
    (set (match_dup 8) (plus:XF (match_dup 6) (match_dup 7)))
    (parallel [(set (match_operand:XF 0 "register_operand" "")
-                  (unspec:XF [(match_dup 8) (match_dup 4)] UNSPEC_FSCALE))
-             (clobber (match_scratch:XF 5 ""))])]
+                  (unspec:XF [(match_dup 8) (match_dup 4)]
+                             UNSPEC_FSCALE_FRACT))
+             (set (match_dup 9)
+                  (unspec:XF [(match_dup 8) (match_dup 4)]
+                             UNSPEC_FSCALE_EXP))])]
   "! TARGET_NO_FANCY_MATH_387 && TARGET_80387
    && flag_unsafe_math_optimizations"
 {
   rtx temp;
   int i;
 
-  for (i=2; i<9; i++)
+  for (i=2; i<10; i++)
     operands[i] = gen_reg_rtx (XFmode);
   temp = standard_80387_constant_rtx (6); /* fldl2t */
   emit_move_insn (operands[2], temp);
@@ -15875,15 +15879,20 @@
    (set (match_dup 4) (minus:XF (match_dup 2) (match_dup 3)))
    (set (match_dup 5) (unspec:XF [(match_dup 4)] UNSPEC_F2XM1))
    (set (match_dup 7) (plus:XF (match_dup 5) (match_dup 6)))
-   (parallel [(set (match_operand:SF 0 "register_operand" "")
-                  (unspec:SF [(match_dup 7) (match_dup 3)] UNSPEC_FSCALE))
-             (clobber (match_scratch:SF 3 ""))])]
+   (parallel [(set (match_dup 8)
+                  (unspec:XF [(match_dup 7) (match_dup 3)]
+                             UNSPEC_FSCALE_FRACT))
+             (set (match_dup 9)
+                  (unspec:XF [(match_dup 7) (match_dup 3)]
+                             UNSPEC_FSCALE_EXP))])
+   (set (match_operand:SF 0 "register_operand" "")
+       (float_truncate:SF (match_dup 8)))]
   "! TARGET_NO_FANCY_MATH_387 && TARGET_80387
    && flag_unsafe_math_optimizations"
 {
   int i;
 
-  for (i=2; i<8; i++)
+  for (i=2; i<10; i++)
     operands[i] = gen_reg_rtx (XFmode);
   emit_move_insn (operands[6], CONST1_RTX (XFmode));  /* fld1 */
 })
@@ -15895,15 +15904,20 @@
    (set (match_dup 4) (minus:XF (match_dup 2) (match_dup 3)))
    (set (match_dup 5) (unspec:XF [(match_dup 4)] UNSPEC_F2XM1))
    (set (match_dup 7) (plus:XF (match_dup 5) (match_dup 6)))
-   (parallel [(set (match_operand:DF 0 "register_operand" "")
-                  (unspec:DF [(match_dup 7) (match_dup 3)] UNSPEC_FSCALE))
-             (clobber (match_scratch:DF 3 ""))])]
+   (parallel [(set (match_dup 8)
+                  (unspec:XF [(match_dup 7) (match_dup 3)]
+                             UNSPEC_FSCALE_FRACT))
+             (set (match_dup 9)
+                  (unspec:XF [(match_dup 7) (match_dup 3)]
+                             UNSPEC_FSCALE_EXP))])
+   (set (match_operand:DF 0 "register_operand" "")
+       (float_truncate:DF (match_dup 8)))]
   "! TARGET_NO_FANCY_MATH_387 && TARGET_80387
    && flag_unsafe_math_optimizations"
 {
   int i;
 
-  for (i=2; i<8; i++)
+  for (i=2; i<10; i++)
     operands[i] = gen_reg_rtx (XFmode);
   emit_move_insn (operands[6], CONST1_RTX (XFmode));  /* fld1 */
 })
@@ -15915,14 +15929,17 @@
    (set (match_dup 5) (unspec:XF [(match_dup 4)] UNSPEC_F2XM1))
    (set (match_dup 7) (plus:XF (match_dup 5) (match_dup 6)))
    (parallel [(set (match_operand:XF 0 "register_operand" "")
-                  (unspec:XF [(match_dup 7) (match_dup 3)] UNSPEC_FSCALE))
-             (clobber (match_scratch:XF 3 ""))])]
+                  (unspec:XF [(match_dup 7) (match_dup 3)]
+                             UNSPEC_FSCALE_FRACT))
+             (set (match_dup 8)
+                  (unspec:XF [(match_dup 7) (match_dup 3)]
+                             UNSPEC_FSCALE_EXP))])]
   "! TARGET_NO_FANCY_MATH_387 && TARGET_80387
    && flag_unsafe_math_optimizations"
 {
   int i;
 
-  for (i=2; i<8; i++)
+  for (i=2; i<9; i++)
     operands[i] = gen_reg_rtx (XFmode);
   emit_move_insn (operands[6], CONST1_RTX (XFmode));  /* fld1 */
 })

diff --git a/gcc/reg-stack.c b/gcc/reg-stack.c
index c3279d0206f55556afb767326e50f8e5dd245f73..2836e63d7ed47b84a1500e5735cc8fa17411f47e 100644 (file)
--- a/gcc/reg-stack.c
+++ b/gcc/reg-stack.c
@@ -249,6 +249,7 @@ static void remove_regno_note (rtx, enum reg_note, unsigned int);
 static int get_hard_regnum (stack, rtx);
 static rtx emit_pop_insn (rtx, stack, rtx, enum emit_where);
 static void emit_swap_insn (rtx, stack, rtx);
+static void swap_to_top(rtx, stack, rtx, rtx);
 static bool move_for_stack_reg (rtx, stack, rtx);
 static int swap_rtx_condition_1 (rtx);
 static int swap_rtx_condition (rtx);
@@ -1034,6 +1035,54 @@ emit_swap_insn (rtx insn, stack regstack, rtx reg)
     emit_insn_before (swap_rtx, insn);
 }
 \f
+/* Emit an insns before INSN to swap virtual register SRC1 with
+   the top of stack and virtual register SRC2 with second stack
+   slot. REGSTACK is the stack state before the swaps, and
+   is updated to reflect the swaps.  A swap insn is represented as a
+   PARALLEL of two patterns: each pattern moves one reg to the other.
+
+   If SRC1 and/or SRC2 are already at the right place, no swap insn
+   is emitted.  */
+
+static void
+swap_to_top (rtx insn, stack regstack, rtx src1, rtx src2)
+{
+  struct stack_def temp_stack;
+  int regno, j, k, temp;
+
+  temp_stack = *regstack;
+
+  /* Place operand 1 at the top of stack.  */
+  regno = get_hard_regnum (&temp_stack, src1);
+  if (regno < 0)
+    abort ();
+  if (regno != FIRST_STACK_REG)
+    {
+      k = temp_stack.top - (regno - FIRST_STACK_REG);
+      j = temp_stack.top;
+
+      temp = temp_stack.reg[k];
+      temp_stack.reg[k] = temp_stack.reg[j];
+      temp_stack.reg[j] = temp;
+    }
+
+  /* Place operand 2 next on the stack.  */
+  regno = get_hard_regnum (&temp_stack, src2);
+  if (regno < 0)
+    abort ();
+  if (regno != FIRST_STACK_REG + 1)
+    {
+      k = temp_stack.top - (regno - FIRST_STACK_REG);
+      j = temp_stack.top - 1;
+
+      temp = temp_stack.reg[k];
+      temp_stack.reg[k] = temp_stack.reg[j];
+      temp_stack.reg[j] = temp;
+    }
+
+  change_stack (insn, regstack, &temp_stack, EMIT_BEFORE);
+}
+\f
 /* Handle a move to or from a stack register in PAT, which is in INSN.
    REGSTACK is the current stack.  Return whether a control flow insn
    was deleted in the process.  */
@@ -1701,7 +1750,6 @@ subst_stack_regs_pat (rtx insn, stack regstack, rtx pat)
 
              case UNSPEC_FPATAN:
              case UNSPEC_FYL2X:
-             case UNSPEC_FSCALE:
                /* These insns operate on the top two stack slots.  */
 
                src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
@@ -1710,42 +1758,7 @@ subst_stack_regs_pat (rtx insn, stack regstack, rtx pat)
                src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
                src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
 
-               {
-                 struct stack_def temp_stack;
-                 int regno, j, k, temp;
-
-                 temp_stack = *regstack;
-
-                 /* Place operand 1 at the top of stack.  */
-                 regno = get_hard_regnum (&temp_stack, *src1);
-                 if (regno < 0)
-                   abort ();
-                 if (regno != FIRST_STACK_REG)
-                   {
-                     k = temp_stack.top - (regno - FIRST_STACK_REG);
-                     j = temp_stack.top;
-
-                     temp = temp_stack.reg[k];
-                     temp_stack.reg[k] = temp_stack.reg[j];
-                     temp_stack.reg[j] = temp;
-                   }
-
-                 /* Place operand 2 next on the stack.  */
-                 regno = get_hard_regnum (&temp_stack, *src2);
-                 if (regno < 0)
-                   abort ();
-                 if (regno != FIRST_STACK_REG + 1)
-                   {
-                     k = temp_stack.top - (regno - FIRST_STACK_REG);
-                     j = temp_stack.top - 1;
-
-                     temp = temp_stack.reg[k];
-                     temp_stack.reg[k] = temp_stack.reg[j];
-                     temp_stack.reg[j] = temp;
-                   }
-
-                 change_stack (insn, regstack, &temp_stack, EMIT_BEFORE);
-               }
+               swap_to_top (insn, regstack, *src1, *src2);
 
                replace_reg (src1, FIRST_STACK_REG);
                replace_reg (src2, FIRST_STACK_REG + 1);
@@ -1768,6 +1781,64 @@ subst_stack_regs_pat (rtx insn, stack regstack, rtx pat)
                replace_reg (dest, FIRST_STACK_REG);
                break;
 
+             case UNSPEC_FSCALE_FRACT:
+               /* These insns operate on the top two stack slots.
+                  first part of double input, double output insn.  */
+
+               src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
+               src2 = get_true_reg (&XVECEXP (pat_src, 0, 1));
+
+               src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
+               src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
+
+               /* Inputs should never die, they are
+                  replaced with outputs.  */
+               if ((src1_note) || (src2_note))
+                 abort();
+
+               swap_to_top (insn, regstack, *src1, *src2);
+
+               /* Push the result back onto stack. Empty stack slot
+                  will be filled in second part of insn. */
+               if (STACK_REG_P (*dest)) {
+                 regstack->reg[regstack->top] = REGNO (*dest);
+                 SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
+                 replace_reg (dest, FIRST_STACK_REG);
+               }
+
+               replace_reg (src1, FIRST_STACK_REG);
+               replace_reg (src2, FIRST_STACK_REG + 1);
+               break;
+
+             case UNSPEC_FSCALE_EXP:
+               /* These insns operate on the top two stack slots./
+                  second part of double input, double output insn.  */
+
+               src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
+               src2 = get_true_reg (&XVECEXP (pat_src, 0, 1));
+
+               src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
+               src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
+
+               /* Inputs should never die, they are
+                  replaced with outputs.  */
+               if ((src1_note) || (src2_note))
+                 abort();
+
+               swap_to_top (insn, regstack, *src1, *src2);
+
+               /* Push the result back onto stack. Fill empty slot from
+                  first part of insn and fix top of stack pointer.  */
+               if (STACK_REG_P (*dest)) {
+                 regstack->reg[regstack->top - 1] = REGNO (*dest);
+                 SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
+                 replace_reg (dest, FIRST_STACK_REG + 1);
+               }
+
+               replace_reg (src1, FIRST_STACK_REG);
+               replace_reg (src2, FIRST_STACK_REG + 1);
+               break;
+
              case UNSPEC_SINCOS_COS:
              case UNSPEC_TAN_ONE:
              case UNSPEC_XTRACT_FRACT: