[libc] Start to refactor riscv platform abstraction to support both 32 and 64 bits versions

This patch enables the compilation of libc for rv32 by unifying the
current rv64 and rv32 implementation into a single rv implementation.

We updated the cmake file to match the new riscv32 arch and force
LIBC_TARGET_ARCHITECTURE to be "riscv" whenever we find "riscv32" or
"riscv64". This is required as LIBC_TARGET_ARCHITECTURE is used in the
path for several platform specific implementations.

Reviewed By: michaelrj

Differential Revision: https://reviews.llvm.org/D148797

Author: mikhailramalho

libc/cmake/modules/LLVMLibCArchitectures.cmake

@@ -150,10 +150,12 @@ elseif(LIBC_TARGET_ARCHITECTURE STREQUAL "aarch64")
   set(LIBC_TARGET_ARCHITECTURE_IS_AARCH64 TRUE)
 elseif(LIBC_TARGET_ARCHITECTURE STREQUAL "x86_64")
   set(LIBC_TARGET_ARCHITECTURE_IS_X86 TRUE)
-elseif(LIBC_TARGET_ARCHITECTURE STREQUAL "riscv32")
-  set(LIBC_TARGET_ARCHITECTURE_IS_RISCV32 TRUE)
 elseif(LIBC_TARGET_ARCHITECTURE STREQUAL "riscv64")
   set(LIBC_TARGET_ARCHITECTURE_IS_RISCV64 TRUE)
+  set(LIBC_TARGET_ARCHITECTURE "riscv")
+elseif(LIBC_TARGET_ARCHITECTURE STREQUAL "riscv32")
+  set(LIBC_TARGET_ARCHITECTURE_IS_RISCV32 TRUE)
+  set(LIBC_TARGET_ARCHITECTURE "riscv")
 else()
   message(FATAL_ERROR
           "Unsupported libc target architecture ${LIBC_TARGET_ARCHITECTURE}")

libc/config/baremetal/riscv32/entrypoints.txt renamed to libc/config/baremetal/riscv/entrypoints.txt

@@ -37,7 +37,7 @@ struct TLSImage {
 
 #if defined(LIBC_TARGET_ARCH_IS_X86_64) ||                                     \
     defined(LIBC_TARGET_ARCH_IS_AARCH64) ||                                    \
-    defined(LIBC_TARGET_ARCH_IS_RISCV64)
+    defined(LIBC_TARGET_ARCH_IS_ANY_RISCV)
 // At the language level, argc is an int. But we use uint64_t as the x86_64
 // ABI specifies it as an 8 byte value. Likewise, in the ARM64 ABI, arguments
 // are usually passed in registers.  x0 is a doubleword register, so this is

libc/config/baremetal/riscv32/headers.txt renamed to libc/config/baremetal/riscv/headers.txt

@@ -30,10 +30,8 @@
 #include "x86_64/FEnvImpl.h"
 #elif defined(LIBC_TARGET_ARCH_IS_ARM)
 #include "arm/FEnvImpl.h"
-#elif defined(LIBC_TARGET_ARCH_IS_RISCV32)
-#include "riscv32/FEnvImpl.h"
-#elif defined(LIBC_TARGET_ARCH_IS_RISCV64)
-#include "riscv64/FEnvImpl.h"
+#elif defined(LIBC_TARGET_ARCH_IS_ANY_RISCV)
+#include "riscv/FEnvImpl.h"
 #else
 
 namespace LIBC_NAMESPACE::fputil {

libc/config/linux/app.h

@@ -18,8 +18,8 @@
 #include "x86_64/FMA.h"
 #elif defined(LIBC_TARGET_ARCH_IS_AARCH64)
 #include "aarch64/FMA.h"
-#elif defined(LIBC_TARGET_ARCH_IS_RISCV64)
-#include "riscv64/FMA.h"
+#elif defined(LIBC_TARGET_ARCH_IS_ANY_RISCV)
+#include "riscv/FMA.h"
 #elif defined(LIBC_TARGET_ARCH_IS_GPU)
 #include "gpu/FMA.h"
 #endif

libc/config/linux/riscv64/entrypoints.txt renamed to libc/config/linux/riscv/entrypoints.txt

@@ -1,13 +1,13 @@
-//===-- riscv32 floating point env manipulation functions -------*- C++ -*-===//
+//===-- riscv floating point env manipulation functions ---------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV32_FENVIMPL_H
-#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV32_FENVIMPL_H
+#ifndef LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV_FENVIMPL_H
+#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV_FENVIMPL_H
 
 #include "src/__support/FPUtil/FPBits.h"
 #include "src/__support/macros/attributes.h" // For LIBC_INLINE_ASM
@@ -177,4 +177,4 @@ LIBC_INLINE int set_env(const fenv_t *envp) {
 } // namespace fputil
 } // namespace LIBC_NAMESPACE
 
-#endif // LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV32_FENVIMPL_H
+#endif // LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV_FENVIMPL_H

libc/config/linux/riscv64/headers.txt renamed to libc/config/linux/riscv/headers.txt

@@ -1,19 +1,19 @@
-//===-- RISCV64 implementations of the fma function -------------*- C++ -*-===//
+//===-- RISCV implementations of the fma function ---------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV64_FMA_H
-#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV64_FMA_H
+#ifndef LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV_FMA_H
+#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV_FMA_H
 
 #include "src/__support/macros/attributes.h" // LIBC_INLINE
 #include "src/__support/macros/properties/architectures.h"
 #include "src/__support/macros/properties/cpu_features.h" // LIBC_TARGET_CPU_HAS_FMA
 
-#if !defined(LIBC_TARGET_ARCH_IS_RISCV64)
+#if !defined(LIBC_TARGET_ARCH_IS_ANY_RISCV)
 #error "Invalid include"
 #endif
 
@@ -47,4 +47,4 @@ LIBC_INLINE cpp::enable_if_t<cpp::is_same_v<T, double>, T> fma(T x, T y, T z) {
 } // namespace fputil
 } // namespace LIBC_NAMESPACE
 
-#endif // LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV64_FMA_H
+#endif // LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV_FMA_H

libc/src/__support/FPUtil/FEnvImpl.h

@@ -6,13 +6,13 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV64_SQRT_H
-#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV64_SQRT_H
+#ifndef LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV_SQRT_H
+#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV_SQRT_H
 
 #include "src/__support/common.h"
 #include "src/__support/macros/properties/architectures.h"
 
-#if !defined(LIBC_TARGET_ARCH_IS_RISCV64)
+#if !defined(LIBC_TARGET_ARCH_IS_ANY_RISCV)
 #error "Invalid include"
 #endif
 
@@ -36,4 +36,4 @@ template <> LIBC_INLINE double sqrt<double>(double x) {
 } // namespace fputil
 } // namespace LIBC_NAMESPACE
 
-#endif // LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV64_SQRT_H
+#endif // LLVM_LIBC_SRC___SUPPORT_FPUTIL_RISCV_SQRT_H

libc/src/__support/FPUtil/FMA.h

@@ -15,8 +15,8 @@
 #include "x86_64/sqrt.h"
 #elif defined(LIBC_TARGET_ARCH_IS_AARCH64)
 #include "aarch64/sqrt.h"
-#elif defined(LIBC_TARGET_ARCH_IS_RISCV64)
-#include "riscv64/sqrt.h"
+#elif defined(LIBC_TARGET_ARCH_IS_ANY_RISCV)
+#include "riscv/sqrt.h"
 #else
 #include "generic/sqrt.h"
 

libc/src/__support/FPUtil/riscv32/FEnvImpl.h renamed to libc/src/__support/FPUtil/riscv/FEnvImpl.h

@@ -1,5 +1,5 @@
 add_header_library(
-  linux_riscv64_util
+  linux_riscv_util
   HDRS
     syscall.h
   DEPENDS

libc/src/__support/FPUtil/riscv64/FMA.h renamed to libc/src/__support/FPUtil/riscv/FMA.h

@@ -1,13 +1,13 @@
-//===--------- inline implementation of riscv64 syscalls ----------* C++ *-===//
+//===--------- inline implementation of riscv syscalls ------------* C++ *-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_RISCV64_SYSCALL_H
-#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_RISCV64_SYSCALL_H
+#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_RISCV_SYSCALL_H
+#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_RISCV_SYSCALL_H
 
 #include "src/__support/common.h"
 
@@ -107,4 +107,4 @@ LIBC_INLINE long syscall_impl(long number, long arg1, long arg2, long arg3,
 #undef REGISTER_CONSTRAINT_5
 #undef REGISTER_CONSTRAINT_6
 
-#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_RISCV64_SYSCALL_H
+#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_RISCV_SYSCALL_H

libc/src/__support/FPUtil/riscv64/sqrt.h renamed to libc/src/__support/FPUtil/riscv/sqrt.h

@@ -19,8 +19,8 @@
 #include "aarch64/syscall.h"
 #elif defined(LIBC_TARGET_ARCH_IS_ARM)
 #include "arm/syscall.h"
-#elif defined(LIBC_TARGET_ARCH_IS_RISCV64)
-#include "riscv64/syscall.h"
+#elif defined(LIBC_TARGET_ARCH_IS_ANY_RISCV)
+#include "riscv/syscall.h"
 #endif
 
 namespace LIBC_NAMESPACE {

libc/src/__support/FPUtil/riscv64/FEnvImpl.h

@@ -45,7 +45,7 @@
 #define LIBC_TARGET_ARCH_IS_AARCH64
 #endif
 
-#if (defined(LIBC_TARGET_ARCH_IS_AARCH64) || defined(LIBC_TARGET_ARCH_IS_ARM))
+#if defined(LIBC_TARGET_ARCH_IS_AARCH64) || defined(LIBC_TARGET_ARCH_IS_ARM)
 #define LIBC_TARGET_ARCH_IS_ANY_ARM
 #endif
 
@@ -57,8 +57,7 @@
 #define LIBC_TARGET_ARCH_IS_RISCV32
 #endif
 
-#if (defined(LIBC_TARGET_ARCH_IS_RISCV64) ||                                   \
-     defined(LIBC_TARGET_ARCH_IS_RISCV32))
+#if defined(LIBC_TARGET_ARCH_IS_RISCV64) || defined(LIBC_TARGET_ARCH_IS_RISCV32)
 #define LIBC_TARGET_ARCH_IS_ANY_RISCV
 #endif