Commit e79e8993e695f6c384f742d09060823f421758ca | zig

author	Andrew Kelley <andrew@ziglang.org> 2019-06-26 11:03:42-04:00
committer	GitHub <noreply@github.com> 2019-06-26 11:03:42-04:00
log	e79e8993e695f6c384f742d09060823f421758ca
tree	842c6fe2ed3c57ea2209730f79d354d32c0280b9
parent	f5af349bd6ab644139ecf4bc0b0761a13a5e6458
parent	f9e26d98711ead110a4c2d2f3032978a5a8c2d9d
signature	Signed by PGP key 4AEE18F83AFDEB23

Merge pull request #2750 from cartr/thumbv4-aeabi

compiler-rt: Support thumb versions older than armv6

1 files changed, 39 insertions(+), 6 deletions(-)

std
- special
  - compiler_rt.zig

std/special/compiler_rt.zig+39-6

 @@ -405,15 +405,15 @@ const use_thumb_1 = usesThumb1(builtin.arch);
 fn usesThumb1(arch: builtin.Arch) bool {
     return switch (arch) {
-        .arm => switch (arch.arm) {
+        .arm => |sub_arch| switch (sub_arch) {
             .v6m => true,
             else => false,
         },
-        .armeb => switch (arch.armeb) {
+        .armeb => |sub_arch| switch (sub_arch) {
             .v6m => true,
             else => false,
         },
-        .thumb => switch (arch.thumb) {
+        .thumb => |sub_arch| switch (sub_arch) {
             .v5,
             .v5te,
             .v4t,
 @@ -423,7 +423,7 @@ fn usesThumb1(arch: builtin.Arch) bool {
             => true,
             else => false,
         },
-        .thumbeb => switch (arch.thumbeb) {
+        .thumbeb => |sub_arch| switch (sub_arch) {
             .v5,
             .v5te,
             .v4t,
 @@ -471,6 +471,22 @@ test "usesThumb1" {
     //etc.
 }
+const use_thumb_1_pre_armv6 = usesThumb1PreArmv6(builtin.arch);
+fn usesThumb1PreArmv6(arch: builtin.Arch) bool {
+    return switch (arch) {
+        .thumb => |sub_arch| switch (sub_arch) {
+            .v5, .v5te, .v4t => true,
+            else => false,
+        },
+        .thumbeb => |sub_arch| switch (sub_arch) {
+            .v5, .v5te, .v4t => true,
+            else => false,
+        },
+        else => false,
+    };
+}
 nakedcc fn __aeabi_memcpy() noreturn {
     @setRuntimeSafety(false);
     if (use_thumb_1) {
 @@ -505,7 +521,16 @@ nakedcc fn __aeabi_memmove() noreturn {
 nakedcc fn __aeabi_memset() noreturn {
     @setRuntimeSafety(false);
-    if (use_thumb_1) {
+    if (use_thumb_1_pre_armv6) {
+        asm volatile (
+            \\ eors    r1, r2
+            \\ eors    r2, r1
+            \\ eors    r1, r2
+            \\ push    {r7, lr}
+            \\ b       memset
+            \\ pop     {r7, pc}
+        );
+    } else if (use_thumb_1) {
         asm volatile (
             \\ mov     r3, r1
             \\ mov     r1, r2
 @@ -527,7 +552,15 @@ nakedcc fn __aeabi_memset() noreturn {
 nakedcc fn __aeabi_memclr() noreturn {
     @setRuntimeSafety(false);
-    if (use_thumb_1) {
+    if (use_thumb_1_pre_armv6) {
+        asm volatile (
+            \\ adds    r2, r1, #0
+            \\ movs    r1, #0
+            \\ push    {r7, lr}
+            \\ bl      memset
+            \\ pop     {r7, pc}
+        );
+    } else if (use_thumb_1) {
         asm volatile (
             \\ mov     r2, r1
             \\ movs    r1, #0