[Issue 13381] One case of array literal that can be stack-allocated

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=13381

--- Comment #6 from bearophile_hugs at eml.cc ---
(In reply to yebblies from comment #5)

> Ideally the optimizer would do this by itself, once the literal is
> stack-allocated.  I suspect it already does in some cases for gdc/ldc.

If I compile this program:


bool foo(in int[] a) {
    return a == [1, 2, 3];
}
void main() {}


With the latest ldc2 with:

ldmd2 -O -release -inline -noboundscheck -output-s test.d


The asm of foo is:

__D4test3fooFxAiZb:
    subl    $20, %esp
    movl    $3, 4(%esp)
    movl    $__D12TypeInfo_xAi6__initZ, (%esp)
    calll   __d_newarrayvT
    movl    $3, 8(%edx)
    movl    $2, 4(%edx)
    movl    $1, (%edx)
    movl    %edx, 12(%esp)
    movl    %eax, 8(%esp)
    movl    28(%esp), %eax
    movl    %eax, 4(%esp)
    movl    24(%esp), %eax
    movl    %eax, (%esp)
    movl    $__D12TypeInfo_Axi6__initZ, 16(%esp)
    calll   __adEq2
    testl   %eax, %eax
    setne   %al
    addl    $20, %esp
    ret $8

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