[clang] [X86] Add support for MS inp functions. (PR #93804)

[Phoebe Wang via cfe-commits]

================
@@ -63,6 +63,82 @@ unsigned __int64 test__emulu(unsigned int a, unsigned int b) {
 // CHECK: [[RES:%[0-9]+]] = mul nuw i64 [[Y]], [[X]]
 // CHECK: ret i64 [[RES]]
 
+
+int test_inp(unsigned short port) {
+  return _inp(port);
+}
+// CHECK-I386-LABEL: define dso_local i32 @test_inp(
+// CHECK-I386-SAME: i16 noundef zeroext [[PORT:%.*]])
+// CHECK-I386-NEXT:  entry:
+// CHECK-I386-NEXT:    [[TMP0:%.*]] = tail call i32 asm sideeffect "inb ${1:b}, ${0:b}", "={ax},N{dx},~{dirflag},~{fpsr},~{flags}"(i16 [[PORT]])
+// CHECK-I386-NEXT:    ret i32 [[TMP0]]
+//
+// CHECK-X64-LABEL: define dso_local i32 @test_inp(
+// CHECK-X64-SAME: i16 noundef [[PORT:%.*]])
+// CHECK-X64-NEXT:  entry:
+// CHECK-X64-NEXT:    [[TMP0:%.*]] = tail call i32 asm sideeffect "inb ${1:b}, ${0:b}", "={ax},N{dx},~{dirflag},~{fpsr},~{flags}"(i16 [[PORT]])
+// CHECK-X64-NEXT:    ret i32 [[TMP0]]
----------------
phoebewang wrote:

These can be merged as
```
// CHECK-LABEL: define dso_local i32 @test_inp(
// CHECK-SAME: i16 noundef zeroext [[PORT:%.*]])
// CHECK-NEXT:  entry:
// CHECK-NEXT:    [[TMP0:%.*]] = tail call i32 asm sideeffect "inb ${1:b}, ${0:b}", "={ax},N{dx},~{dirflag},~{fpsr},~{flags}"(i16 [[PORT]])
// CHECK-NEXT:    ret i32 [[TMP0]]
```

The same to others.

https://github.com/llvm/llvm-project/pull/93804