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authorRalf Baechle <ralf@linux-mips.org>1998-03-03 01:22:27 +0000
committerRalf Baechle <ralf@linux-mips.org>1998-03-03 01:22:27 +0000
commitf9bbe9da79dbc8557c74efeb158b431cd67ace52 (patch)
tree3220d014a35f9d88a48668a1468524e988daebff /arch/i386/math-emu/reg_u_sub.S
parent3d697109c1ff85ef563aec3d5e113ef225ed2792 (diff)
Upgrade to 2.1.73.
Diffstat (limited to 'arch/i386/math-emu/reg_u_sub.S')
-rw-r--r--arch/i386/math-emu/reg_u_sub.S74
1 files changed, 28 insertions, 46 deletions
diff --git a/arch/i386/math-emu/reg_u_sub.S b/arch/i386/math-emu/reg_u_sub.S
index 891670260..092f956c0 100644
--- a/arch/i386/math-emu/reg_u_sub.S
+++ b/arch/i386/math-emu/reg_u_sub.S
@@ -4,21 +4,23 @@
| |
| Core floating point subtraction routine. |
| |
- | Copyright (C) 1992,1993,1995 |
- | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
- | Australia. E-mail billm@jacobi.maths.monash.edu.au |
+ | Copyright (C) 1992,1993,1995,1997 |
+ | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
+ | E-mail billm@suburbia.net |
| |
| Call from C as: |
- | void reg_u_sub(FPU_REG *arg1, FPU_REG *arg2, FPU_REG *answ, |
+ | int FPU_u_sub(FPU_REG *arg1, FPU_REG *arg2, FPU_REG *answ, |
| int control_w) |
+ | Return value is the tag of the answer, or-ed with FPU_Exception if |
+ | one was raised, or -1 on internal error. |
| |
+---------------------------------------------------------------------------*/
/*
- | Kernel subtraction routine reg_u_sub(reg *arg1, reg *arg2, reg *answ).
- | Takes two valid reg f.p. numbers (TW_Valid), which are
+ | Kernel subtraction routine FPU_u_sub(reg *arg1, reg *arg2, reg *answ).
+ | Takes two valid reg f.p. numbers (TAG_Valid), which are
| treated as unsigned numbers,
- | and returns their difference as a TW_Valid or TW_Zero f.p.
+ | and returns their difference as a TAG_Valid or TAG_Zero f.p.
| number.
| The first number (arg1) must be the larger.
| The returned number is normalized.
@@ -30,7 +32,7 @@
#include "control_w.h"
.text
-ENTRY(reg_u_sub)
+ENTRY(FPU_u_sub)
pushl %ebp
movl %esp,%ebp
pushl %esi
@@ -39,28 +41,9 @@ ENTRY(reg_u_sub)
movl PARAM1,%esi /* source 1 */
movl PARAM2,%edi /* source 2 */
-
-#ifdef DENORM_OPERAND
- cmpl EXP_UNDER,EXP(%esi)
- jg xOp1_not_denorm
-
- call SYMBOL_NAME(denormal_operand)
- orl %eax,%eax
- jnz fpu_Arith_exit
-
-xOp1_not_denorm:
- cmpl EXP_UNDER,EXP(%edi)
- jg xOp2_not_denorm
-
- call SYMBOL_NAME(denormal_operand)
- orl %eax,%eax
- jnz fpu_Arith_exit
-
-xOp2_not_denorm:
-#endif DENORM_OPERAND
-
- movl EXP(%esi),%ecx
- subl EXP(%edi),%ecx /* exp1 - exp2 */
+
+ movl PARAM6,%ecx
+ subl PARAM7,%ecx /* exp1 - exp2 */
#ifdef PARANOID
/* source 2 is always smaller than source 1 */
@@ -81,10 +64,8 @@ xOp2_not_denorm:
movl SIGL(%edi),%ebx /* register ls word */
movl PARAM3,%edi /* destination */
- movl EXP(%esi),%edx
- movl %edx,EXP(%edi) /* Copy exponent to destination */
-/* movb SIGN(%esi),%dl
- movb %dl,SIGN(%edi) */ /* Copy the sign from the first arg */
+ movl PARAM6,%edx
+ movw %dx,EXP(%edi) /* Copy exponent to destination */
xorl %edx,%edx /* register extension */
@@ -93,8 +74,8 @@ xOp2_not_denorm:
| right the required number of |
| places. |
+--------------------------------------*/
-L_shift_r:
- cmpl $32,%ecx /* shrd only works for 0..31 bits */
+
+ cmpw $32,%cx /* shrd only works for 0..31 bits */
jnc L_more_than_31
/* less than 32 bits */
@@ -104,7 +85,7 @@ L_shift_r:
jmp L_shift_done
L_more_than_31:
- cmpl $64,%ecx
+ cmpw $64,%cx
jnc L_more_than_63
subb $32,%cl
@@ -210,7 +191,7 @@ L_subtr:
jnz L_must_be_zero
/* Shift left 64 bits */
- subl $64,EXP(%edi)
+ subw $64,EXP(%edi)
xchg %edx,%eax
jmp fpu_reg_round
@@ -221,17 +202,17 @@ L_must_be_zero:
#endif PARANOID
/* The result is zero */
- movb TW_Zero,TAG(%edi)
- movl $0,EXP(%edi) /* exponent */
+ movw $0,EXP(%edi) /* exponent */
movl $0,SIGL(%edi)
movl $0,SIGH(%edi)
- jmp L_exit /* %eax contains zero */
+ movl TAG_Zero,%eax
+ jmp L_exit
L_shift_32:
movl %ebx,%eax
movl %edx,%ebx
movl $0,%edx
- subl $32,EXP(%edi) /* Can get underflow here */
+ subw $32,EXP(%edi) /* Can get underflow here */
/* We need to shift left by 1 - 31 bits */
L_shift_1:
@@ -241,7 +222,7 @@ L_shift_1:
shld %cl,%ebx,%eax
shld %cl,%edx,%ebx
shl %cl,%edx
- subl %ecx,EXP(%edi) /* Can get underflow here */
+ subw %cx,EXP(%edi) /* Can get underflow here */
L_round:
jmp fpu_reg_round /* Round the result */
@@ -277,11 +258,12 @@ L_bugged:
call EXCEPTION
pop %ebx
jmp L_error_exit
-#endif PARANOID
-
L_error_exit:
- movl $1,%eax
+ movl $-1,%eax
+
+#endif PARANOID
+
L_exit:
popl %ebx
popl %edi