x86_64 fenv support (untested; at least known to build successfully)

diff --git a/src/fenv/x86_64/fenv.s b/src/fenv/x86_64/fenv.s
new file mode 100644 (file)
index 0000000..3ed2275
--- /dev/null
+++ b/src/fenv/x86_64/fenv.s
@@ -0,0 +1,88 @@
+2:     not %edi
+       sub $32,%rsp
+       fnstenv (%rsp)
+       and %edi,4(%rsp)
+       or %esi,4(%rsp)
+       fldenv (%rsp)
+       stmxcsr (%rsp)
+       and %edi,(%rsp)
+       ldmxcsr (%rsp)
+       add $32,%rsp
+       ret
+
+.global feclearexcept
+feclearexcept: 
+       xor %eax,%eax
+       xor %esi,%esi
+       test %edi,%edi
+       jnz 2b
+       ret
+
+.global feraiseexcept
+feraiseexcept: 
+       xor %eax,%eax
+       mov %edi,%esi
+       xor %edi,%edi
+       test %esi,%esi
+       jnz 2b
+       ret
+
+.global fesetround
+fesetround:
+       xor %eax,%eax
+       sub $32,%rsp
+       fnstenv (%rsp)
+       andb $0xf3,1(%rsp)
+       or %edi,(%rsp)
+       fldenv (%rsp)
+       stmxcsr (%rsp)
+       shl $3,%edi
+       andb $0x9f,1(%rsp)
+       or %edi,(%rsp)
+       ldmxcsr (%rsp)
+       add $32,%rsp
+       ret
+
+.global fegetround
+fegetround:
+       push %rax
+       stmxcsr (%rsp)
+       pop %rax
+       shr $3,%eax
+       and $0xc,%ah
+       ret
+
+.global fegetenv
+fegetenv:
+       xor %eax,%eax
+       fnstenv (%rdi)
+       stmxcsr 28(%rdi)
+       ret
+
+.global fesetenv
+fesetenv:
+       xor %eax,%eax
+       inc %rdi
+       jz 1f
+       fldenv -1(%rdi)
+       ldmxcsr 27(%rdi)
+       ret
+1:     push %rax
+       push %rax
+       push %rax
+       pushq $0x37f
+       fldenv (%rsp)
+       pushq $0x1f80
+       ldmxcsr (%rsp)
+       add $40,%rsp
+       ret
+
+.global fetestexcept
+fetestexcept:
+       push %rax
+       stmxcsr (%rsp)
+       pop %rsi
+       fnstsw %ax
+       or %esi,%eax
+       and %edi,%eax
+       ret