Merge "riscv64: fenv implementation." am: 81f0bdb6f3

Original change: https://android-review.googlesource.com/c/platform/bionic/+/2256273

Change-Id: I26049c50955827b495b5d179af0d47d582e4932c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

libm/Android.bp

@@ -344,6 +344,13 @@ cc_library {
             version_script: ":libm.arm64.map",
         },
 
+        riscv64: {
+            srcs: [
+                "riscv64/fenv.c",
+            ],
+            version_script: ":libm.riscv64.map",
+        },
+
         x86: {
             srcs: [
                 "i387/fenv.c",
@@ -572,6 +579,14 @@ genrule {
     cmd: "$(location generate-version-script) arm64 $(in) $(out)",
 }
 
+genrule {
+    name: "libm.riscv64.map",
+    out: ["libm.riscv64.map"],
+    srcs: ["libm.map.txt"],
+    tools: ["generate-version-script"],
+    cmd: "$(location generate-version-script) riscv64 $(in) $(out)",
+}
+
 genrule {
     name: "libm.x86.map",
     out: ["libm.x86.map"],

libm/NOTICE

@@ -309,6 +309,34 @@ SUCH DAMAGE.
 
 -------------------------------------------------------------------
 
+Copyright (C) 2022 The Android Open Source Project
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+ * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in
+   the documentation and/or other materials provided with the
+   distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.
+
+-------------------------------------------------------------------
+
 Copyright (c) 1985, 1993
    The Regents of the University of California.  All rights reserved.
 

libm/riscv64/fenv.c

@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <fenv.h>
+#include <stdint.h>
+
+const fenv_t __fe_dfl_env = 0;
+
+int fegetenv(fenv_t* envp) {
+  __asm__ __volatile__("frcsr %0" : "=r"(*envp));
+  return 0;
+}
+
+int fesetenv(const fenv_t* envp) {
+  fenv_t env;
+  fegetenv(&env);
+  if (*envp != env) {
+    __asm__ __volatile__("fscsr %z0" : : "r"(*envp));
+  }
+  return 0;
+}
+
+int feclearexcept(int excepts) {
+  __asm__ __volatile__("csrc fflags, %0" : : "r"(excepts & FE_ALL_EXCEPT));
+  return 0;
+}
+
+int fegetexceptflag(fexcept_t* flagp, int excepts) {
+  *flagp = fetestexcept(excepts & FE_ALL_EXCEPT);
+  return 0;
+}
+
+int fesetexceptflag(const fexcept_t* flagp, int excepts) {
+  feclearexcept((~*flagp) & excepts);
+  feraiseexcept(*flagp & excepts);
+  return 0;
+}
+
+int feraiseexcept(int excepts) {
+  __asm__ __volatile__("csrs fflags, %0" : : "r"(excepts));
+  return 0;
+}
+
+int fetestexcept(int excepts) {
+  int flags;
+  __asm__ __volatile__("frflags %0" : "=r"(flags));
+  return flags & excepts;
+}
+
+int fegetround(void) {
+  int rm;
+  __asm__ __volatile__("frrm %0" : "=r"(rm));
+  return rm;
+}
+
+int fesetround(int round) {
+  if (round < FE_TONEAREST || round > FE_UPWARD) return -1;
+  __asm__ __volatile__("fsrm %z0" : : "r"(round));
+  return 0;
+}
+
+int feholdexcept(fenv_t* envp) {
+  fegetenv(envp);
+  feclearexcept(FE_ALL_EXCEPT);
+  return 0;
+}
+
+int feupdateenv(const fenv_t* envp) {
+  int excepts = fetestexcept(FE_ALL_EXCEPT);
+  fesetenv(envp);
+  feraiseexcept(excepts);
+  return 0;
+}
+
+int feenableexcept(int mask __unused) {
+  return -1;
+}
+
+int fedisableexcept(int mask __unused) {
+  return 0;
+}
+
+int fegetexcept(void) {
+  return 0;
+}