[Builtin] [ARM] Update CMake to support the build of armv6m

Summary:
Setting -DCOMPILER_RT_TEST_TARGET_TRIPLE=armv6m-none-eabi  will enable the build of builtin functions ARMv6m.
Currently, only those asms that support armv6m are added.

TODO:All asm sin ARM_EABI_Sources are ported for thumb1 so Thumb1_EABI_Sources will be deprecated.

Reviewers: rengolin, compnerd

Reviewed By: compnerd

Subscribers: aemerson, mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D28463

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@292504 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/cmake/base-config-ix.cmake b/cmake/base-config-ix.cmake
index 71d1499..6f9f151 100644
--- a/cmake/base-config-ix.cmake
+++ b/cmake/base-config-ix.cmake
@@ -172,6 +172,7 @@
       else()
         test_target_arch(arm "" "-march=armv7-a" "-mfloat-abi=soft")
         test_target_arch(armhf "" "-march=armv7-a" "-mfloat-abi=hard")
+        test_target_arch(armv6m "" "-march=armv6m" "-mfloat-abi=soft")
       endif()
     elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "aarch32")
       test_target_arch(aarch32 "" "-march=armv8-a")
diff --git a/cmake/builtin-config-ix.cmake b/cmake/builtin-config-ix.cmake
index 8cb4ca1..dc2ec16 100644
--- a/cmake/builtin-config-ix.cmake
+++ b/cmake/builtin-config-ix.cmake
@@ -24,7 +24,7 @@
 
 
 set(ARM64 aarch64)
-set(ARM32 arm armhf)
+set(ARM32 arm armhf armv6m)
 set(X86 i386 i686)
 set(X86_64 x86_64)
 set(MIPS32 mips mipsel)
diff --git a/lib/builtins/CMakeLists.txt b/lib/builtins/CMakeLists.txt
index 3cf7861..775dafe 100644
--- a/lib/builtins/CMakeLists.txt
+++ b/lib/builtins/CMakeLists.txt
@@ -302,6 +302,12 @@
   arm/umodsi3.S
   ${GENERIC_SOURCES})
 
+set(thumb1_SOURCES
+  arm/divsi3.S
+  arm/udivsi3.S
+  arm/comparesf2.S
+  ${GENERIC_SOURCES})
+
 set(arm_EABI_SOURCES
   arm/aeabi_cdcmp.S
   arm/aeabi_cdcmpeq_check_nan.c
@@ -320,6 +326,20 @@
   arm/aeabi_memset.S
   arm/aeabi_uidivmod.S
   arm/aeabi_uldivmod.S)
+
+set(thumb1_EABI_SOURCES
+  arm/aeabi_cdcmpeq_check_nan.c
+  arm/aeabi_cfcmpeq_check_nan.c
+  arm/aeabi_div0.c
+  arm/aeabi_drsub.c
+  arm/aeabi_fcmp.S
+  arm/aeabi_frsub.c
+  arm/aeabi_idivmod.S
+  arm/aeabi_memcmp.S
+  arm/aeabi_memcpy.S
+  arm/aeabi_memmove.S
+  arm/aeabi_uidivmod.S)
+
 set(arm_Thumb1_JT_SOURCES
   arm/switch16.S
   arm/switch32.S
@@ -401,6 +421,10 @@
     ${arm_SOURCES}
     ${arm_EABI_SOURCES}
     ${arm_Thumb1_SOURCES})
+
+  set(thumb1_SOURCES
+    ${thumb1_SOURCES}
+    ${thumb1_EABI_SOURCES})
 endif()
 
 set(aarch64_SOURCES
@@ -431,7 +455,7 @@
 set(arm64_SOURCES ${aarch64_SOURCES})
 
 # macho_embedded archs
-set(armv6m_SOURCES ${GENERIC_SOURCES})
+set(armv6m_SOURCES ${thumb1_SOURCES})
 set(armv7m_SOURCES ${arm_SOURCES})
 set(armv7em_SOURCES ${arm_SOURCES})