compiler-rt: Fix build on armv6

Fixes Issue #445

Signed-off-by: Khem Raj <raj.khem@gmail.com>

2 files changed, 75 insertions, 0 deletions

diff --git a/recipes-devtools/clang/clang/0030-compiler-rt-Use-mcr-based-barrier-on-armv6.patch b/recipes-devtools/clang/clang/0030-compiler-rt-Use-mcr-based-barrier-on-armv6.patch
new file mode 100644
index 0000000..458dbcc
--- /dev/null
+++ b/recipes-devtools/clang/clang/0030-compiler-rt-Use-mcr-based-barrier-on-armv6.patch
@@ -0,0 +1,74 @@
+From 97123bf7bc7cc2a55c3dfb5006be5dd66c46d790 Mon Sep 17 00:00:00 2001
+From: Khem Raj <raj.khem@gmail.com>
+Date: Wed, 24 Mar 2021 00:32:09 -0700
+Subject: [PATCH] compiler-rt: Use mcr based barrier on armv6
+
+dsb is an armv7 instruction and wont work when we are building for armv6.
+
+Upstream-Status: Pending
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+---
+ compiler-rt/lib/builtins/arm/sync-ops.h | 8 ++++----
+ compiler-rt/lib/builtins/assembly.h     | 8 ++++++++
+ 2 files changed, 12 insertions(+), 4 deletions(-)
+
+diff --git a/compiler-rt/lib/builtins/arm/sync-ops.h b/compiler-rt/lib/builtins/arm/sync-ops.h
+index c9623249e5d2..7a26170741ad 100644
+--- a/compiler-rt/lib/builtins/arm/sync-ops.h
++++ b/compiler-rt/lib/builtins/arm/sync-ops.h
+@@ -19,14 +19,14 @@
+   .thumb;                                                                      \
+   .syntax unified;                                                             \
+   DEFINE_COMPILERRT_THUMB_FUNCTION(__sync_fetch_and_##op)                      \
+-  dmb;                                                                         \
++  DMB;                                                                         \
+   mov r12, r0;                                                                 \
+   LOCAL_LABEL(tryatomic_##op) : ldrex r0, [r12];                               \
+   op(r2, r0, r1);                                                              \
+   strex r3, r2, [r12];                                                         \
+   cmp r3, #0;                                                                  \
+   bne LOCAL_LABEL(tryatomic_##op);                                             \
+-  dmb;                                                                         \
++  DMB;                                                                         \
+   bx lr
+ 
+ #define SYNC_OP_8(op)                                                          \
+@@ -35,14 +35,14 @@
+   .syntax unified;                                                             \
+   DEFINE_COMPILERRT_THUMB_FUNCTION(__sync_fetch_and_##op)                      \
+   push {r4, r5, r6, lr};                                                       \
+-  dmb;                                                                         \
++  DMB;                                                                         \
+   mov r12, r0;                                                                 \
+   LOCAL_LABEL(tryatomic_##op) : ldrexd r0, r1, [r12];                          \
+   op(r4, r5, r0, r1, r2, r3);                                                  \
+   strexd r6, r4, r5, [r12];                                                    \
+   cmp r6, #0;                                                                  \
+   bne LOCAL_LABEL(tryatomic_##op);                                             \
+-  dmb;                                                                         \
++  DMB;                                                                         \
+   pop { r4, r5, r6, pc }
+ 
+ #define MINMAX_4(rD, rN, rM, cmp_kind)                                         \
+diff --git a/compiler-rt/lib/builtins/assembly.h b/compiler-rt/lib/builtins/assembly.h
+index f6ce6a9fccff..5c6cd9376ac4 100644
+--- a/compiler-rt/lib/builtins/assembly.h
++++ b/compiler-rt/lib/builtins/assembly.h
+@@ -181,6 +181,14 @@
+   JMP(ip)
+ #endif
+ 
++#if __ARM_ARCH >= 7
++#define DMB dmb
++#elif __ARM_ARCH >= 6
++#define DMB mcr p15, #0, r0, c7, c10, #5
++#else
++#error Only use this with ARMv6+
++#endif
++
+ #if defined(USE_THUMB_2)
+ #define WIDE(op) op.w
+ #else
+-- 
+2.31.0
+
diff --git a/recipes-devtools/clang/common.inc b/recipes-devtools/clang/common.inc
index b6af90c..9de7674 100644
--- a/recipes-devtools/clang/common.inc
+++ b/recipes-devtools/clang/common.inc
@@ -38,6 +38,7 @@ SRC_URI = "\
     file://0027-compiler-rt-Include-stddef.h.patch \
     file://0028-llvm-Do-not-use-find_library-for-ncurses.patch \
     file://0029-llvm-Recognize-yoe-and-poky-as-OE-distro.patch \
+    file://0030-compiler-rt-Use-mcr-based-barrier-on-armv6.patch \
 "
 # Fallback to no-PIE if not set
 GCCPIE ??= ""