Add preliminary support for inline assembly for msp430.

2 files changed, 174 insertions, 1 deletions

diff --git a/src/doc/unstable-book/src/language-features/asm-experimental-arch.md b/src/doc/unstable-book/src/language-features/asm-experimental-arch.md
index ec97eaa8b2b..37fd67447c1 100644
--- a/src/doc/unstable-book/src/language-features/asm-experimental-arch.md
+++ b/src/doc/unstable-book/src/language-features/asm-experimental-arch.md
@@ -15,6 +15,7 @@ This feature tracks `asm!` and `global_asm!` support for the following architect
 - BPF
 - SPIR-V
 - AVR
+- MSP430
 
 ## Register classes
 
@@ -39,6 +40,7 @@ This feature tracks `asm!` and `global_asm!` support for the following architect
 | AVR          | `reg_pair`     | `r3r2` .. `r25r24`, `X`, `Z`       | `r`                  |
 | AVR          | `reg_iw`       | `r25r24`, `X`, `Z`                 | `w`                  |
 | AVR          | `reg_ptr`      | `X`, `Z`                           | `e`                  |
+| MSP430       | `reg`          | `r[0-15]`                          | `r`                  |
 
 > **Notes**:
 > - NVPTX doesn't have a fixed register set, so named registers are not supported.
@@ -67,6 +69,7 @@ This feature tracks `asm!` and `global_asm!` support for the following architect
 | BPF          | `wreg`                          | `alu32`        | `i8` `i16` `i32`                        |
 | AVR          | `reg`, `reg_upper`              | None           | `i8`                                    |
 | AVR          | `reg_pair`, `reg_iw`, `reg_ptr` | None           | `i16`                                   |
+| MSP430       | `reg`                           | None           | `i8`, `i16`                             |
 
 ## Register aliases
 
@@ -80,13 +83,22 @@ This feature tracks `asm!` and `global_asm!` support for the following architect
 | AVR          | `XL`          | `r26`     |
 | AVR          | `ZH`          | `r31`     |
 | AVR          | `ZL`          | `r30`     |
+| MSP430       | `r0`          | `pc`      |
+| MSP430       | `r1`          | `sp`      |
+| MSP430       | `r2`          | `sr`      |
+| MSP430       | `r3`          | `cg`      |
+| MSP430       | `r4`          | `fp`      |
+
+> **Notes**:
+> - TI does not mandate a frame pointer for MSP430, but toolchains are allowed
+    to use one; LLVM uses `r4`.
 
 ## Unsupported registers
 
 | Architecture | Unsupported register                    | Reason                                                                                                                                                                              |
 | ------------ | --------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | All          | `sp`                                    | The stack pointer must be restored to its original value at the end of an asm code block.                                                                                           |
-| All          | `fr` (Hexagon), `$fp` (MIPS), `Y` (AVR) | The frame pointer cannot be used as an input or output.                                                                                                                             |
+| All          | `fr` (Hexagon), `$fp` (MIPS), `Y` (AVR), `r4` (MSP430) | The frame pointer cannot be used as an input or output.                                                                                                                             |
 | All          | `r19` (Hexagon)                         | This is used internally by LLVM as a "base pointer" for functions with complex stack frames.                                                                                        |
 | MIPS         | `$0` or `$zero`                         | This is a constant zero register which can't be modified.                                                                                                                           |
 | MIPS         | `$1` or `$at`                           | Reserved for assembler.                                                                                                                                                             |
@@ -95,6 +107,7 @@ This feature tracks `asm!` and `global_asm!` support for the following architect
 | MIPS         | `$ra`                                   | Return address cannot be used as inputs or outputs.                                                                                                                                 |
 | Hexagon      | `lr`                                    | This is the link register which cannot be used as an input or output.                                                                                                               |
 | AVR          | `r0`, `r1`, `r1r0`                      | Due to an issue in LLVM, the `r0` and `r1` registers cannot be used as inputs or outputs.  If modified, they must be restored to their original values before the end of the block. |
+|MSP430        | `r0`, `r2`, `r3`                        | These are the program counter, status register, and constant generator respectively. Neither the status register nor constant generator can be written to.                          |
 
 ## Template modifiers
 
@@ -115,3 +128,5 @@ This feature tracks `asm!` and `global_asm!` support for the following architect
 These flags registers must be restored upon exiting the asm block if the `preserves_flags` option is set:
 - AVR
   - The status register `SREG`.
+- MSP430
+  - The status register `r2`.
diff --git a/src/test/assembly/asm/msp430-types.rs b/src/test/assembly/asm/msp430-types.rs
new file mode 100644
index 00000000000..6cfb86e276e
--- /dev/null
+++ b/src/test/assembly/asm/msp430-types.rs
@@ -0,0 +1,158 @@
+// min-llvm-version: 13.0
+// assembly-output: emit-asm
+// compile-flags: --target msp430-none-elf
+// needs-llvm-components: msp430
+
+#![feature(no_core, lang_items, rustc_attrs, asm_sym, asm_experimental_arch, asm_const)]
+#![crate_type = "rlib"]
+#![no_core]
+#![allow(non_camel_case_types)]
+
+#[rustc_builtin_macro]
+macro_rules! asm {
+    () => {};
+}
+#[rustc_builtin_macro]
+macro_rules! concat {
+    () => {};
+}
+
+#[lang = "sized"]
+trait Sized {}
+#[lang = "copy"]
+trait Copy {}
+
+type ptr = *const i16;
+
+impl Copy for i8 {}
+impl Copy for i16 {}
+impl Copy for i32 {}
+impl Copy for i64 {}
+impl Copy for ptr {}
+
+macro_rules! check {
+    ($func:ident $ty:ident $class:ident) => {
+        #[no_mangle]
+        pub unsafe fn $func(x: $ty) -> $ty {
+            let y;
+            asm!("mov {}, {}", lateout($class) y, in($class) x);
+            y
+        }
+    };
+}
+
+macro_rules! checkb {
+    ($func:ident $ty:ident $class:ident) => {
+        #[no_mangle]
+        pub unsafe fn $func(x: $ty) -> $ty {
+            let y;
+            asm!("mov.b {}, {}", lateout($class) y, in($class) x);
+            y
+        }
+    };
+}
+
+macro_rules! check_reg {
+    ($func:ident $ty:ident $reg:tt) => {
+        #[no_mangle]
+        pub unsafe fn $func(x: $ty) -> $ty {
+            let y;
+            asm!(concat!("mov ", $reg, ", ", $reg), lateout($reg) y, in($reg) x);
+            y
+        }
+    };
+}
+
+macro_rules! check_regb {
+    ($func:ident $ty:ident $reg:tt) => {
+        #[no_mangle]
+        pub unsafe fn $func(x: $ty) -> $ty {
+            let y;
+            asm!(concat!("mov.b ", $reg, ", ", $reg), lateout($reg) y, in($reg) x);
+            y
+        }
+    };
+}
+
+extern "C" {
+    fn extern_func();
+    static extern_static: i8;
+}
+
+// CHECK-LABEL: sym_fn
+// CHECK: ;APP
+// CHECK: call extern_func
+// CHECK: ;NO_APP
+#[no_mangle]
+pub unsafe fn sym_fn() {
+    asm!("call {}", sym extern_func);
+}
+
+// CHECK-LABEL: sym_static
+// CHECK: ;APP
+// CHECK: mov.b extern_static, r{{[0-9]+}}
+// CHECK: ;NO_APP
+#[no_mangle]
+pub unsafe fn sym_static() -> i8 {
+    let y;
+    asm!("mov.b {1}, {0}", lateout(reg) y, sym extern_static);
+    y
+}
+
+// CHECK-LABEL: add_const:
+// CHECK: ;APP
+// CHECK: add.b #5, r{{[0-9]+}}
+// CHECK: ;NO_APP
+#[no_mangle]
+pub unsafe fn add_const() -> i8 {
+    let y;
+    asm!("add.b #{number}, {}", out(reg) y, number = const 5);
+    y
+}
+
+// CHECK-LABEL: mov_postincrement:
+// CHECK: ;APP
+// CHECK: mov @r5+, r{{[0-9]+}}
+// CHECK: ;NO_APP
+#[no_mangle]
+pub unsafe fn mov_postincrement(mut x: *const i16) -> (i16, *const i16) {
+    let y;
+    asm!("mov @r5+, {0}", out(reg) y, inlateout("r5") x);
+    (y, x)
+}
+
+// CHECK-LABEL: reg_i8:
+// CHECK: ;APP
+// CHECK: mov r{{[0-9]+}}, r{{[0-9]+}}
+// CHECK: ;NO_APP
+check!(reg_i8 i8 reg);
+
+// CHECK-LABEL: reg_i16:
+// CHECK: ;APP
+// CHECK: mov r{{[0-9]+}}, r{{[0-9]+}}
+// CHECK: ;NO_APP
+check!(reg_i16 i16 reg);
+
+// CHECK-LABEL: reg_i8b:
+// CHECK: ;APP
+// CHECK: mov.b r{{[0-9]+}}, r{{[0-9]+}}
+// CHECK: ;NO_APP
+checkb!(reg_i8b i8 reg);
+
+// CHECK-LABEL: r5_i8:
+// CHECK: ;APP
+// CHECK: mov r5, r5
+// CHECK: ;NO_APP
+check_reg!(r5_i8 i8 "r5");
+
+// CHECK-LABEL: r5_i16:
+// CHECK: ;APP
+// CHECK: mov r5, r5
+// CHECK: ;NO_APP
+check_reg!(r5_i16 i16 "r5");
+
+// CHECK-LABEL: r5_i8b:
+// CHECK: ;APP
+// CHECK: mov.b r5, r5
+// CHECK: ;NO_APP
+check_regb!(r5_i8b i8 "r5");