Merge pull request managarm#1664 from no92/fenv

fenv unstubbing + improvements

Author: Mathewnd

options/ansi/generic/fenv.cpp

@@ -1,24 +1,30 @@
 
 #include <bits/ensure.h>
 #include <fenv.h>
+#include <type_traits>
 
 // The functions that are not in this file but are defined in the header
 // are implemented like musl does in assembly.
 extern "C" __attribute__((__visibility__("hidden"))) int __fesetround(int);
 
-int fegetexceptflag(fexcept_t *, int) {
-	__ensure(!"Not implemented");
-	__builtin_unreachable();
+// our implementation of fegetexceptflag requires that this holds.
+static_assert(std::is_integral_v<fexcept_t>);
+
+int fegetexceptflag(fexcept_t *fe, int excepts) {
+	*fe = fetestexcept(excepts);
+	return 0;
 }
 
-int feholdexcept(fenv_t *) {
-	__ensure(!"Not implemented");
-	__builtin_unreachable();
+int feholdexcept(fenv_t *fe) {
+	fegetenv(fe);
+	feclearexcept(FE_ALL_EXCEPT);
+	return 0;
 }
 
-int fesetexceptflag(const fexcept_t *, int) {
-	__ensure(!"Not implemented");
-	__builtin_unreachable();
+int fesetexceptflag(const fexcept_t *fe, int mask) {
+	feclearexcept(~*fe & mask);
+	feraiseexcept(*fe & mask);
+	return 0;
 }
 
 int fesetround(int r) {
@@ -37,7 +43,9 @@ int fesetround(int r) {
 	return __fesetround(r);
 }
 
-int feupdateenv(const fenv_t *) {
-	__ensure(!"Not implemented");
-	__builtin_unreachable();
+int feupdateenv(const fenv_t *fe) {
+	int e = fetestexcept(FE_ALL_EXCEPT);
+	fesetenv(fe);
+	feraiseexcept(e);
+	return 0;
 }

options/internal/aarch64/setjmp.S

@@ -1,5 +1,7 @@
 // vim: ft=arm64asm
 
+#include "mlibc-asm/helpers.h"
+
 .extern __sigsetjmp
 
 .type __setjmp, "function"
@@ -63,5 +65,6 @@ _longjmp:
 	cmp w1, 0
 	csinc w0, w1, wzr, ne
 	br x30
-.section .note.GNU-stack,"",%progbits
+
+GNU_STACK_NOTE()
 

options/internal/m68k/fenv.S

@@ -1,5 +1,7 @@
 #include <bits/ansi/fenv.h>
 
+#include "mlibc-asm/helpers.h"
+
 .global feclearexcept
 .type feclearexcept,@function
 feclearexcept:
@@ -108,4 +110,4 @@ fetestexcept:
 	and.l 4(%sp), %d0
 	rts
 
-.section .note.GNU-stack,"",%progbits
+GNU_STACK_NOTE()

options/internal/x86/fenv.S

@@ -1,3 +1,5 @@
+#include "mlibc-asm/helpers.h"
+
 # The functions below are taken from musl.
 
 .hidden __hwcap
@@ -165,4 +167,4 @@ fetestexcept:
 1:	and %ecx,%eax
 	ret
 
-.section .note.GNU-stack,"",%progbits
+GNU_STACK_NOTE()

options/internal/x86_64/fenv.S

@@ -1,3 +1,5 @@
+#include "mlibc-asm/helpers.h"
+
 # The functions below are taken from musl.
 .global feclearexcept
 .type feclearexcept,@function
@@ -98,5 +100,4 @@ fetestexcept:
 	and %edi,%eax
 	ret
 
-.section .note.GNU-stack,"",%progbits
-
+GNU_STACK_NOTE()