• d-bugmail puremagic.com (101/101) Aug 28 2022 https://issues.dlang.org/show_bug.cgi?id=23307

d-bugmail puremagic.com writes:

https://issues.dlang.org/show_bug.cgi?id=23307

          Issue ID: 23307
           Summary: [REG][CODEGEN][SIMD] wrong codegen with inlined local
                    functions + SIMD
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Severity: regression
          Priority: P1
         Component: dmd
          Assignee: nobody puremagic.com
          Reporter: contact auburnsounds.com

Consider the following program:


------ main.d --------

import core.simd;

alias __m128i = int4;

uint bitwiseRotateRight_uint(const uint value, const uint count)
{
    assert(count < 8 * uint.sizeof);
    return cast(uint) ((value >> count) | (value << (uint.sizeof * 8 -
count)));
}


__m128i _mm_sha256rnds2_epu32(__m128i a, __m128i b, __m128i k)
{

    static uint Ch(uint x, uint y, uint z) 
    { 
        return z ^ (x & (y ^ z)); 
    }

    static uint Maj(uint x, uint y, uint z)
    { 
        return (x & y) | (z & (x ^ y)); 
    }

    static uint sum0(uint x)
    { 
        return bitwiseRotateRight_uint(x, 2) ^ bitwiseRotateRight_uint(x, 13) ^
bitwiseRotateRight_uint(x, 22); 
    }

    static uint sum1(uint x)
    { 
        return bitwiseRotateRight_uint(x, 6) ^ bitwiseRotateRight_uint(x, 11) ^
bitwiseRotateRight_uint(x, 25); 
    }

    int4 dst;
    int4 a4 = cast(int4) a;
    int4 b4 = cast(int4) b;
    int4 k4 = cast(int4) k;

    const A0 = b4.array[3];
    const B0 = b4.array[2];
    const C0 = a4.array[3];
    const D0 = a4.array[2];
    const E0 = b4.array[1];
    const F0 = b4.array[0];
    const G0 = a4.array[1];
    const H0 = a4.array[0];
    const W_K0 = k4.array[0];
    const W_K1 = k4.array[1];
    const A1 = Ch(E0, F0, G0) + sum1(E0) + W_K0 + H0 + Maj(A0, B0, C0) +
sum0(A0);
    const B1 = A0;
    const C1 = B0;
    const D1 = C0;
    const E1 = Ch(E0, F0, G0) + sum1(E0) + W_K0 + H0 + D0;
    const F1 = E0;
    const G1 = F0;
    const H1 = G0;
    const A2 = Ch(E1, F1, G1) + sum1(E1) + W_K1 + H1 + Maj(A1, B1, C1) +
sum0(A1);
    const B2 = A1;
    const C2 = B1;
    const D2 = C1;
    const E2 = Ch(E1, F1, G1) + sum1(E1) + W_K1 + H1 + D1;
    const F2 = E1;
    const G2 = F1;
    const H2 = G1;

    dst.ptr[3] = A2;
    dst.ptr[2] = B2;
    dst.ptr[1] = E2;
    dst.ptr[0] = F2;

    return cast(__m128i) dst;
}

void main(string[] args)
{
    __m128i a = [15, 20, 130, 12345];
    __m128i b = [15, 20, 130, 12345];
    __m128i k = [15, 20, 130, 12345];
    __m128i result = _mm_sha256rnds2_epu32(a, b, k);
    assert(result.array == [1384123044, -2050674062, 327754346, 956342016]);
}


-----------------------

Crash it with dmd -O -inline, it won't pass the assertion.
Result is a wrong value.

Workarounds:
- LDC
- DMD without -O
- DMD without -inline
- pragma(inline, false) in the sub-functions

This worked on DMD 2.095 to 2.097, so I labelled as regression.

Thanks!!!!

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