783290 - IonMonkey: LMathD should allow memory operands on x86

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Jan de Mooij [:jandem]]

Attachment: Patch

On top of bug 783272 this removes 5 more instructions from the loop in 3d-cube DrawLine:

for (; i < NumPix; i++) {
    Num += NumAdd;
    if (Num >= Den) {
        Num -= Den;
        x += IncX1;
        y += IncY1;
    }
    x += IncX2;
    y += IncY2;
}


With range analysis + bug 762095 there's not much more we can optimize - we will emit something like:

0x1ca78c0:	cmpl   $0x0,0x140ba00
0x1ca78c7:	jne    0x1ca7a79
0x1ca78db:	cmp    %ecx,%edi
0x1ca78dd:	jge    0x1ca79f7
0x1ca78f8:	addsd  %xmm6,%xmm5
0x1ca7903:	ucomisd %xmm2,%xmm5
0x1ca7907:	jp     0x1ca798a
0x1ca790d:	jb     0x1ca798a
0x1ca7949:	subsd  %xmm2,%xmm5
0x1ca7954:	addsd  %xmm0,%xmm3
0x1ca795f:	addsd  %xmm1,%xmm4
0x1ca798a:	addsd  0x28(%esp),%xmm3
0x1ca79a8:	addsd  0x30(%esp),%xmm4
0x1ca79be:	add    $0x1,%edi
0x1ca79eb:	jmp    0x1ca78c0

Comment 1

[Jan de Mooij [:jandem]]

https://hg.mozilla.org/projects/ionmonkey/rev/2b38908d7d54