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[X86]Add support for __outbyte/word/dword and __inbyte/word/dword #93774

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Merged
merged 5 commits into from
Jun 21, 2024
Merged

[X86]Add support for __outbyte/word/dword and __inbyte/word/dword #93774

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17c3fc9
Add support for _outp{|w|d}
MalaySanghi May 30, 2024
f0f4675
remove memory constraint and fix definition.
MalaySanghi May 30, 2024
794872b
merge checks
MalaySanghi May 31, 2024
4534c72
implement byte/word/dword versions
MalaySanghi Jun 20, 2024
b438d3f
replace volatile with __volatile__
MalaySanghi Jun 20, 2024
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14 changes: 14 additions & 0 deletions clang/lib/Headers/intrin.h
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Original file line number Diff line number Diff line change
Expand Up @@ -348,6 +348,20 @@ static inline unsigned long _inpd(unsigned short port) {
return ret;
}

static inline int _outp(unsigned short port, int data) {
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Can we change it to __outbyte instead?

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There's 2 differences between _outp and __outbyte.

First, the newer intrinsics don't return a value.

Second, __outbyte signature is

void __outbyte(
   unsigned short Port,
   unsigned char Data
);

Note that the second input is unsigned char instead of int. This is likely because _outp is supposed to write a byte.

Other than that, I have verified that renaming to __outbyte works and is functionally equivalent.
When lowered via microsoft's cl, the asm is identical.

__asm__ volatile("outb %b0, %w1" : : "a"(data), "Nd"(port));
return data;
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Return the direct data seems useless. Did you check if MSVC returns the same value or it actually reads from the port and returns the old data?

}

static inline unsigned short _outpw(unsigned short port, unsigned short data) {
__asm__ volatile("outw %w0, %w1" : : "a"(data), "Nd"(port));
return data;
}

static inline unsigned long _outpd(unsigned short port, unsigned long data) {
__asm__ volatile("outl %k0, %w1" : : "a"(data), "Nd"(port));
return data;
}
#endif

#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__)
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27 changes: 27 additions & 0 deletions clang/test/CodeGen/X86/ms-x86-intrinsics.c
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Expand Up @@ -88,6 +88,33 @@ unsigned long test_inpd(unsigned short port) {
// CHECK: [[TMP0:%.*]] = tail call i32 asm sideeffect "inl ${1:w}, ${0:k}", "={ax},N{dx},~{dirflag},~{fpsr},~{flags}"(i16 [[PORT]])
// CHECK-NEXT: ret i32 [[TMP0]]

int test_outp(unsigned short port, int data) {
return _outp(port, data);
}
// CHECK-LABEL: i32 @test_outp(
// CHECK-SAME: [[PORT:%.*]],
// CHECK-SAME: [[DATA:%.*]])
// CHECK: tail call void asm sideeffect "outb ${0:b}, ${1:w}", "{ax},N{dx},~{dirflag},~{fpsr},~{flags}"(i32 [[DATA]], i16 [[PORT]])
// CHECK-NEXT: ret i32 [[DATA]]

unsigned short test_outpw(unsigned short port, unsigned short data) {
return _outpw(port, data);
}
// CHECK-LABEL: i16 @test_outpw(
// CHECK-SAME: [[PORT:%.*]],
// CHECK-SAME: [[DATA:%.*]])
// CHECK: tail call void asm sideeffect "outw ${0:w}, ${1:w}", "{ax},N{dx},~{dirflag},~{fpsr},~{flags}"(i16 [[DATA]], i16 [[PORT]])
// CHECK-NEXT: ret i16 [[DATA]]

unsigned long test_outpd(unsigned short port, unsigned long data) {
return _outpd(port, data);
}
// CHECK-LABEL: i32 @test_outpd(
// CHECK-SAME: [[PORT:%.*]],
// CHECK-SAME: [[DATA:%.*]])
// CHECK: tail call void asm sideeffect "outl ${0:k}, ${1:w}", "{ax},N{dx},~{dirflag},~{fpsr},~{flags}"(i32 [[DATA]], i16 [[PORT]])
// CHECK-NEXT: ret i32 [[DATA]]

#if defined(__x86_64__)

char test__readgsbyte(unsigned long Offset) {
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