[libc] Add hardware implementations of ceil and ceilf for aarch64.

This change also introduces a new source layout for adding machine
specific and generic implementations. To keep the scope of this change
small, this new pattern is only applied for ceil, ceilf and ceill.
Follow up changes will switch all math functions in to the new pattern.

Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D95850

10 files changed, 183 insertions, 36 deletions

diff --git a/libc/src/math/CMakeLists.txt b/libc/src/math/CMakeLists.txt
index 34b7dfcd4306..ac4ee312fb81 100644
--- a/libc/src/math/CMakeLists.txt
+++ b/libc/src/math/CMakeLists.txt
@@ -1,3 +1,41 @@
+add_subdirectory(generic)
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_MACHINE})
+  add_subdirectory(${LIBC_TARGET_MACHINE})
+endif()
+
+function(add_math_entrypoint_object name)
+  # We prefer machine specific implementation if available. Hence we check
+  # that first and retrun early if we are able to add an alias target for the
+  # machine specific implementation.
+  get_fq_target_name("${LIBC_TARGET_MACHINE}.${name}" fq_machine_specific_target_name)
+  if(TARGET ${fq_machine_specific_target_name})
+    add_entrypoint_object(
+      ${name}
+      ALIAS
+      DEPENDS
+        .${LIBC_TARGET_MACHINE}.${name}
+    )
+    return()
+  endif()
+
+  get_fq_target_name("generic.${name}" fq_generic_target_name)
+  if(TARGET ${fq_generic_target_name})
+    add_entrypoint_object(
+      ${name}
+      ALIAS
+      DEPENDS
+        .generic.${name}
+    )
+    return()
+  endif()
+
+  message(FATAL_ERROR "No machine specific or generic implementation found for ${name}.")
+endfunction()
+
+add_math_entrypoint_object(ceil)
+add_math_entrypoint_object(ceilf)
+add_math_entrypoint_object(ceill)
+
 add_object_library(
   math_utils
   SRCS
@@ -129,42 +167,6 @@ add_entrypoint_object(
 )
 
 add_entrypoint_object(
-  ceil
-  SRCS
-    ceil.cpp
-  HDRS
-    ceil.h
-  DEPENDS
-    libc.utils.FPUtil.fputil
-  COMPILE_OPTIONS
-    -O2
-)
-
-add_entrypoint_object(
-  ceilf
-  SRCS
-    ceilf.cpp
-  HDRS
-    ceilf.h
-  DEPENDS
-    libc.utils.FPUtil.fputil
-  COMPILE_OPTIONS
-    -O2
-)
-
-add_entrypoint_object(
-  ceill
-  SRCS
-    ceill.cpp
-  HDRS
-    ceill.h
-  DEPENDS
-    libc.utils.FPUtil.fputil
-  COMPILE_OPTIONS
-    -O2
-)
-
-add_entrypoint_object(
   floor
   SRCS
     floor.cpp
diff --git a/libc/src/math/aarch64/CMakeLists.txt b/libc/src/math/aarch64/CMakeLists.txt
new file mode 100644
index 000000000000..716fbe3bf7c6
--- /dev/null
+++ b/libc/src/math/aarch64/CMakeLists.txt
@@ -0,0 +1,19 @@
+add_entrypoint_object(
+  ceil
+  SRCS
+    ceil.cpp
+  HDRS
+    ../ceil.h
+  COMPILE_OPTIONS
+    -O2
+)
+
+add_entrypoint_object(
+  ceilf
+  SRCS
+    ceilf.cpp
+  HDRS
+    ../ceilf.h
+  COMPILE_OPTIONS
+    -O2
+)
diff --git a/libc/src/math/aarch64/ceil.cpp b/libc/src/math/aarch64/ceil.cpp
new file mode 100644
index 000000000000..c39dbfc50993
--- /dev/null
+++ b/libc/src/math/aarch64/ceil.cpp
@@ -0,0 +1,25 @@
+//===-- Implementation of the ceil function for aarch64 -------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/math/ceil.h"
+#include "src/__support/common.h"
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(double, ceil, (double x)) {
+  double y;
+  __asm__ __volatile__("ldr d0, %1\n"
+                       "frintp d0, d0\n"
+                       "str d0, %0\n"
+                       : "=m"(y)
+                       : "m"(x)
+                       : "d0");
+  return y;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/math/aarch64/ceilf.cpp b/libc/src/math/aarch64/ceilf.cpp
new file mode 100644
index 000000000000..1d8047757835
--- /dev/null
+++ b/libc/src/math/aarch64/ceilf.cpp
@@ -0,0 +1,25 @@
+//===-- Implementation of the ceilf function for aarch64 ------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/math/ceilf.h"
+#include "src/__support/common.h"
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(float, ceilf, (float x)) {
+  float y;
+  __asm__ __volatile__("ldr s0, %1\n"
+                       "frintp s0, s0\n"
+                       "str s0, %0\n"
+                       : "=m"(y)
+                       : "m"(x)
+                       : "s0");
+  return y;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
new file mode 100644
index 000000000000..6c481b57b3d6
--- /dev/null
+++ b/libc/src/math/generic/CMakeLists.txt
@@ -0,0 +1,35 @@
+add_entrypoint_object(
+  ceil
+  SRCS
+    ceil.cpp
+  HDRS
+    ../ceil.h
+  DEPENDS
+    libc.utils.FPUtil.fputil
+  COMPILE_OPTIONS
+    -O2
+)
+
+add_entrypoint_object(
+  ceilf
+  SRCS
+    ceilf.cpp
+  HDRS
+    ../ceilf.h
+  DEPENDS
+    libc.utils.FPUtil.fputil
+  COMPILE_OPTIONS
+    -O2
+)
+
+add_entrypoint_object(
+  ceill
+  SRCS
+    ceill.cpp
+  HDRS
+    ../ceill.h
+  DEPENDS
+    libc.utils.FPUtil.fputil
+  COMPILE_OPTIONS
+    -O2
+)
diff --git a/libc/src/math/ceil.cpp b/libc/src/math/generic/ceil.cpp
index 7c59c938acff..7c59c938acff 100644
--- a/libc/src/math/ceil.cpp
+++ b/libc/src/math/generic/ceil.cpp
diff --git a/libc/src/math/ceilf.cpp b/libc/src/math/generic/ceilf.cpp
index 9093ee196617..9093ee196617 100644
--- a/libc/src/math/ceilf.cpp
+++ b/libc/src/math/generic/ceilf.cpp
diff --git a/libc/src/math/ceill.cpp b/libc/src/math/generic/ceill.cpp
index 23edb7a441c8..23edb7a441c8 100644
--- a/libc/src/math/ceill.cpp
+++ b/libc/src/math/generic/ceill.cpp
diff --git a/libc/test/src/math/CMakeLists.txt b/libc/test/src/math/CMakeLists.txt
index 8764d57a1413..841e4db5a22b 100644
--- a/libc/test/src/math/CMakeLists.txt
+++ b/libc/test/src/math/CMakeLists.txt
@@ -1070,3 +1070,5 @@ add_fp_unittest(
     libc.src.math.fmaf
     libc.utils.FPUtil.fputil
 )
+
+add_subdirectory(generic)
diff --git a/libc/test/src/math/generic/CMakeLists.txt b/libc/test/src/math/generic/CMakeLists.txt
new file mode 100644
index 000000000000..d1bf53271f09
--- /dev/null
+++ b/libc/test/src/math/generic/CMakeLists.txt
@@ -0,0 +1,39 @@
+add_fp_unittest(
+  ceil_test
+  NEED_MPFR
+  SUITE
+    libc_math_unittests
+  SRCS
+    ../ceil_test.cpp
+  DEPENDS
+    libc.include.math
+    libc.src.math.generic.ceil
+    libc.utils.FPUtil.fputil
+)
+
+add_fp_unittest(
+  ceilf_test
+  NEED_MPFR
+  SUITE
+    libc_math_unittests
+  SRCS
+    ../ceilf_test.cpp
+  DEPENDS
+    libc.include.math
+    libc.src.math.generic.ceilf
+    libc.utils.FPUtil.fputil
+)
+
+add_fp_unittest(
+  ceill_test
+  NEED_MPFR
+  SUITE
+    libc_math_unittests
+  SRCS
+    ../ceill_test.cpp
+  DEPENDS
+    libc.include.math
+    libc.src.math.generic.ceill
+    libc.utils.FPUtil.fputil
+)
+