[PATCH v2 10/10] i386: Do not raise inexact exception on trunc/truncf

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

It is not allowed anymore on ISO C23.

Checked on x86_64-linux-gnu and i686-linux-gnu.
---
 sysdeps/i386/fpu/{s_trunc.S => s_trunc.c}   | 37 +++++++++++----------
 sysdeps/i386/fpu/{s_truncf.S => s_truncf.c} | 37 +++++++++++----------
 2 files changed, 38 insertions(+), 36 deletions(-)
 rename sysdeps/i386/fpu/{s_trunc.S => s_trunc.c} (61%)
 rename sysdeps/i386/fpu/{s_truncf.S => s_truncf.c} (61%)

diff --git a/sysdeps/i386/fpu/s_trunc.S b/sysdeps/i386/fpu/s_trunc.c
similarity index 61%
rename from sysdeps/i386/fpu/s_trunc.S
rename to sysdeps/i386/fpu/s_trunc.c
index 40e45c9f9c..5880964499 100644
--- a/sysdeps/i386/fpu/s_trunc.S
+++ b/sysdeps/i386/fpu/s_trunc.c
@@ -1,5 +1,5 @@
-/* Truncate double value.
-   Copyright (C) 1997-2024 Free Software Foundation, Inc.
+/* Round to integer, toward zero.  i386 version.
+   Copyright (C) 2024 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -16,22 +16,23 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#include <machine/asm.h>
+#define NO_MATH_REDIRECT
+#include <math.h>
+#include <fenv_private.h>
 #include <libm-alias-double.h>
 
-ENTRY(__trunc)
-	fldl	4(%esp)
-	subl	$32, %esp
-	cfi_adjust_cfa_offset (32)
-	fnstenv	4(%esp)
-	movl	$0xc00, %edx
-	orl	4(%esp), %edx
-	movl	%edx, (%esp)
-	fldcw	(%esp)
-	frndint
-	fldenv	4(%esp)
-	addl	$32, %esp
-	cfi_adjust_cfa_offset (-32)
-	ret
-END(__trunc)
+double
+__trunc (double x)
+{
+  fenv_t fenv;
+  double r;
+
+  libc_feholdexcept_setround_387 (&fenv, FE_TOWARDZERO);
+  asm volatile ("frndint" : "=t" (r) : "0" (x));
+  /* Preserve "invalid" exceptions from sNaN input.  */
+  fenv.__status_word |= libc_fetestexcept_387 (FE_INVALID);
+  libc_fesetenv_387 (&fenv);
+
+  return r;
+}
 libm_alias_double (__trunc, trunc)
diff --git a/sysdeps/i386/fpu/s_truncf.S b/sysdeps/i386/fpu/s_truncf.c
similarity index 61%
rename from sysdeps/i386/fpu/s_truncf.S
rename to sysdeps/i386/fpu/s_truncf.c
index 0b26e09d61..037099024f 100644
--- a/sysdeps/i386/fpu/s_truncf.S
+++ b/sysdeps/i386/fpu/s_truncf.c
@@ -1,5 +1,5 @@
-/* Truncate float value.
-   Copyright (C) 1997-2024 Free Software Foundation, Inc.
+/* Round to integer, toward zero.  i386 version.
+   Copyright (C) 2024 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -16,22 +16,23 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#include <machine/asm.h>
+#define NO_MATH_REDIRECT
+#include <math.h>
+#include <fenv_private.h>
 #include <libm-alias-float.h>
 
-ENTRY(__truncf)
-	flds	4(%esp)
-	subl	$32, %esp
-	cfi_adjust_cfa_offset (32)
-	fnstenv	4(%esp)
-	movl	$0xc00, %edx
-	orl	4(%esp), %edx
-	movl	%edx, (%esp)
-	fldcw	(%esp)
-	frndint
-	fldenv	4(%esp)
-	addl	$32, %esp
-	cfi_adjust_cfa_offset (-32)
-	ret
-END(__truncf)
+float
+__truncf (float x)
+{
+  fenv_t fenv;
+  float r;
+
+  libc_feholdexcept_setround_387 (&fenv, FE_TOWARDZERO);
+  asm volatile ("frndint" : "=t" (r) : "0" (x));
+  /* Preserve "invalid" exceptions from sNaN input.  */
+  fenv.__status_word |= libc_fetestexcept_387 (FE_INVALID);
+  libc_fesetenv_387 (&fenv);
+
+  return r;
+}
 libm_alias_float (__trunc, trunc)
-- 
2.34.1