Commit aff2e47821aaad5cac74ed8a3cac2e72283b594b | zig

author	vegecode <justin.b.alexander1@gmail.com> 2019-04-07 22:17:21-05:00
committer	Andrew Kelley <andrew@ziglang.org> 2019-04-10 12:35:16-04:00
log	aff2e47821aaad5cac74ed8a3cac2e72283b594b
tree	a34d36b0b6a4e628a5be0bb883e03607bf877194
parent	dea1027f9799e6ce0f7f2594c6b555d9675c281a

compiler-rt: correct use_thumb_1 flag

The flag is for generating correct arm-thumb interwork veneers in the
assembly code __aeabi_{memcpy,memset,etc} functions.

Armv6m only does thumb code generation regardless of whether arm or
thumb is selected and armv6t2 uses the newer thumb 2 set. All other
versions that zig supports pre-armv7 need the veneers and hence the
flag. Armv5 is actually armv5t.

Relevant code from clang/lib/Basic/Targets/Arm.cpp

```c
bool ARMTargetInfo::isThumb() const {
  return ArchISA == llvm::ARM::ISAKind::THUMB;
  }

bool ARMTargetInfo::supportsThumb() const {
  return CPUAttr.count('T') || ArchVersion >= 6;
}

bool ARMTargetInfo::supportsThumb2() const {
  return CPUAttr.equals("6T2") ||
    (ArchVersion >= 7 && !CPUAttr.equals("8M_BASE"));
}
```

Also see

http://www.llvm.org/svn/llvm-project/llvm/trunk/lib/Target/ARM/ARM.td

1 files changed, 69 insertions(+), 8 deletions(-)

std
- special
  - compiler_rt.zig

std/special/compiler_rt.zig+69-8

...	...	@@ -253,14 +253,75 @@ const is_arm_arch = switch (builtin.arch) {
253	253
254	254	const is_arm_32 = is_arm_arch and !is_arm_64;
255	255
256		const use_thumb_1 = is_arm_32 and switch (builtin.arch.arm) {
257		builtin.Arch.Arm32.v6,
258		builtin.Arch.Arm32.v6m,
259		builtin.Arch.Arm32.v6k,
260		builtin.Arch.Arm32.v6t2,
261		=> true,
262		else => false,
263		};
	256	const use_thumb_1 = usesThumb1(builtin.arch);
	257
	258	fn usesThumb1(arch: builtin.Arch) bool {
	259	return switch (arch) {
	260	.arm => switch (arch.arm) {
	261	.v6m => true,
	262	else => false,
	263	},
	264	.armeb => switch (arch.armeb) {
	265	.v6m => true,
	266	else => false,
	267	},
	268	.thumb => switch (arch.thumb) {
	269	.v5,
	270	.v5te,
	271	.v4t,
	272	.v6,
	273	.v6m,
	274	.v6k,
	275	=> true,
	276	else => false,
	277	},
	278	.thumbeb => switch (arch.thumbeb) {
	279	.v5,
	280	.v5te,
	281	.v4t,
	282	.v6,
	283	.v6m,
	284	.v6k,
	285	=> true,
	286	else => false,
	287	},
	288	else => false,
	289	};
	290	}
	291
	292	test "usesThumb1" {
	293	testing.expect(usesThumb1(builtin.Arch{ .arm = .v6m }));
	294	testing.expect(!usesThumb1(builtin.Arch{ .arm = .v5 }));
	295	//etc.
	296
	297	testing.expect(usesThumb1(builtin.Arch{ .armeb = .v6m }));
	298	testing.expect(!usesThumb1(builtin.Arch{ .armeb = .v5 }));
	299	//etc.
	300
	301	testing.expect(usesThumb1(builtin.Arch{ .thumb = .v5 }));
	302	testing.expect(usesThumb1(builtin.Arch{ .thumb = .v5te }));
	303	testing.expect(usesThumb1(builtin.Arch{ .thumb = .v4t }));
	304	testing.expect(usesThumb1(builtin.Arch{ .thumb = .v6 }));
	305	testing.expect(usesThumb1(builtin.Arch{ .thumb = .v6k }));
	306	testing.expect(usesThumb1(builtin.Arch{ .thumb = .v6m }));
	307	testing.expect(!usesThumb1(builtin.Arch{ .thumb = .v6t2 }));
	308	//etc.
	309
	310	testing.expect(usesThumb1(builtin.Arch{ .thumbeb = .v5 }));
	311	testing.expect(usesThumb1(builtin.Arch{ .thumbeb = .v5te }));
	312	testing.expect(usesThumb1(builtin.Arch{ .thumbeb = .v4t }));
	313	testing.expect(usesThumb1(builtin.Arch{ .thumbeb = .v6 }));
	314	testing.expect(usesThumb1(builtin.Arch{ .thumbeb = .v6k }));
	315	testing.expect(usesThumb1(builtin.Arch{ .thumbeb = .v6m }));
	316	testing.expect(!usesThumb1(builtin.Arch{ .thumbeb = .v6t2 }));
	317	//etc.
	318
	319	testing.expect(!usesThumb1(builtin.Arch{ .aarch64 = .v8 }));
	320	testing.expect(!usesThumb1(builtin.Arch{ .aarch64_be = .v8 }));
	321	testing.expect(!usesThumb1(builtin.Arch.x86_64));
	322	testing.expect(!usesThumb1(builtin.Arch.riscv32));
	323	//etc.
	324	}
264	325
265	326	nakedcc fn __aeabi_uidivmod() void {
266	327	@setRuntimeSafety(false);