[Bug d/107241] New: std.bitmanip.bigEndianToNative et al not inlined

[Bug d/107241] New: std.bitmanip.bigEndianToNative et al not inlined

[witold.baryluk+gcc at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107241

            Bug ID: 107241
           Summary: std.bitmanip.bigEndianToNative et al not inlined
           Product: gcc
           Version: 12.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: d
          Assignee: ibuclaw at gdcproject dot org
          Reporter: witold.baryluk+gcc at gmail dot com
  Target Milestone: ---

gdc fails to inline number of small functions that should fully inline and end
in single instruction.

on amd64 / x86, for example std.bitmanip.bigEndianToNative causes a chain of
calls / jumps, even with @attribute("flatten")



import std.bitmanip;
import gcc.attributes;

@attribute("flatten")
size_t f(char[] b) {
    return std.bitmanip.bigEndianToNative!(size_t,
8)(cast(ubyte[8])(b[2..10]));
}




gcc -O3 -march=znver2 -frelease


pure nothrow @nogc @safe ulong
std.bitmanip.swapEndian!(ulong).swapEndian(const(ulong)):
        mov     rax, rdi
        bswap   rax
        ret
pure nothrow @nogc @safe ulong std.bitmanip.endianToNativeImpl!(true, ulong,
8uL).endianToNativeImpl(ubyte[8]):
        jmp     pure nothrow @nogc @safe ulong
std.bitmanip.swapEndian!(ulong).swapEndian(const(ulong))
pure nothrow @nogc @safe ulong std.bitmanip.bigEndianToNative!(ulong,
8uL).bigEndianToNative(ubyte[8]):
        jmp     pure nothrow @nogc @safe ulong
std.bitmanip.endianToNativeImpl!(true, ulong, 8uL).endianToNativeImpl(ubyte[8])
ulong example.f(char[]):
        mov     rdi, QWORD PTR [rsi+2]
        jmp     pure nothrow @nogc @safe ulong
std.bitmanip.bigEndianToNative!(ulong, 8uL).bigEndianToNative(ubyte[8])




No issues with LDC.

ulong example.f(char[]):
        mov     rax, qword ptr [rsi + 2]
        bswap   rax
        ret



godbolt: https://godbolt.org/z/Pj3f7oGso

[Bug d/107241] std.bitmanip.bigEndianToNative et al not inlined

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107241

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Hmm:
__attribute__((weak))
ulong swapEndian (const ulong val)

[Bug d/107241] std.bitmanip.bigEndianToNative et al not inlined

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107241

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #1)
> Hmm:
> __attribute__((weak))
> ulong swapEndian (const ulong val)

Note this is definitely a front-end issue .

[Bug d/107241] std.bitmanip.bigEndianToNative et al not inlined

[ibuclaw at gdcproject dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107241

Iain Buclaw <ibuclaw at gdcproject dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |DUPLICATE

--- Comment #3 from Iain Buclaw <ibuclaw at gdcproject dot org> ---
Looks like pr102765 to me.

*** This bug has been marked as a duplicate of bug 102765 ***