patch-1.3.76 linux/arch/i386/math-emu/reg_constant.c

• Lines: 106
• Date: Tue Mar 19 13:45:01 1996
• Orig file: v1.3.75/linux/arch/i386/math-emu/reg_constant.c
• Orig date: Thu Jun 2 10:28:27 1994

diff -u --recursive --new-file v1.3.75/linux/arch/i386/math-emu/reg_constant.c linux/arch/i386/math-emu/reg_constant.c
@@ -3,9 +3,9 @@
  |                                                                           |
  | All of the constant FPU_REGs                                              |
  |                                                                           |
- | Copyright (C) 1992,1993,1994                                              |
- |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
- |                       Australia.  E-mail   billm@vaxc.cc.monash.edu.au    |
+ | Copyright (C) 1992,1993,1994,1996                                         |
+ |                     W. Metzenthen, 22 Parker St, Ormond, Vic 3163,        |
+ |                     Australia.  E-mail   billm@jacobi.maths.monash.edu.au |
  |                                                                           |
  |                                                                           |
  +---------------------------------------------------------------------------*/
@@ -14,6 +14,7 @@
 #include "fpu_emu.h"
 #include "status_w.h"
 #include "reg_constant.h"
+#include "control_w.h"
 
 
 FPU_REG const CONST_1    = { SIGN_POS, TW_Valid, EXP_BIAS,
@@ -56,7 +57,7 @@
 
 
 
-static void fld_const(FPU_REG const *c)
+static void fld_const(FPU_REG const *c, int adj)
 {
   FPU_REG *st_new_ptr;
 
@@ -67,50 +68,58 @@
     }
   push();
   reg_move(c, st_new_ptr);
+  st_new_ptr->sigl += adj;  /* For all our fldxxx constants, we don't need to
+			       borrow or carry. */
   clear_C1();
 }
 
+/* A fast way to find out whether x is one of RC_DOWN or RC_CHOP
+   (and not one of RC_RND or RC_UP).
+   */
+#define DOWN_OR_CHOP(x)  (x & RC_DOWN)
 
-static void fld1(void)
+static void fld1(int rc)
 {
-  fld_const(&CONST_1);
+  fld_const(&CONST_1, 0);
 }
 
-static void fldl2t(void)
+static void fldl2t(int rc)
 {
-  fld_const(&CONST_L2T);
+  fld_const(&CONST_L2T, (rc == RC_UP) ? 1 : 0);
 }
 
-static void fldl2e(void)
+static void fldl2e(int rc)
 {
-  fld_const(&CONST_L2E);
+  fld_const(&CONST_L2E, DOWN_OR_CHOP(rc) ? -1 : 0);
 }
 
-static void fldpi(void)
+static void fldpi(int rc)
 {
-  fld_const(&CONST_PI);
+  fld_const(&CONST_PI, DOWN_OR_CHOP(rc) ? -1 : 0);
 }
 
-static void fldlg2(void)
+static void fldlg2(int rc)
 {
-  fld_const(&CONST_LG2);
+  fld_const(&CONST_LG2, DOWN_OR_CHOP(rc) ? -1 : 0);
 }
 
-static void fldln2(void)
+static void fldln2(int rc)
 {
-  fld_const(&CONST_LN2);
+  fld_const(&CONST_LN2, DOWN_OR_CHOP(rc) ? -1 : 0);
 }
 
-static void fldz(void)
+static void fldz(int rc)
 {
-  fld_const(&CONST_Z);
+  fld_const(&CONST_Z, 0);
 }
 
-static FUNC constants_table[] = {
-  fld1, fldl2t, fldl2e, fldpi, fldlg2, fldln2, fldz, FPU_illegal
+typedef void (*FUNC_RC)(int);
+
+static FUNC_RC constants_table[] = {
+  fld1, fldl2t, fldl2e, fldpi, fldlg2, fldln2, fldz, (FUNC_RC)FPU_illegal
 };
 
 void fconst(void)
 {
-  (constants_table[FPU_rm])();
+  (constants_table[FPU_rm])(control_word & CW_RC);
 }