SDKZSPF LSI, SDKZSPF Datasheet - Page 330

• Manufacturer Part Number: SDKZSPF
• Manufacturer: LSI

Specifications of SDKZSPF

• Lead Free Status / Rohs Status: Supplier Unconfirmed

D-2
The compiler generates code to copy the arguments to the proper
accumulator registers, if required. Eliminating the steps required in
copying the arguments minimizes execution time. Copying the
arguments is not required if:
Execution time can also be minimized by not requiring the result to be
copied to its destination. Copying the result is not required if:
For example, the following code is legal:
However, it is more efficient to use:
In the first case (b = L_maca(b,x,y)), two copies are required—one to
move {r3 r2} to {r1 r0} for the argument, and another to move
{r3 r2} to {r1 r0} to the destination. The second case (b =
L_macb(b,x,y)) requires no extra copies.
Note that a call to an L_*a function clobbers any variable declared with
an accum_a, and a call to an L_*b function clobbers any variable
declared with an accum_b. In the following example, the value of variable
a is equivalent to b after the L_maca function call:
L-Intrinsic Functions
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The long argument already exists in the appropriate accumulator (for
example, if you call L_maca with a variable declared as type
accum_a).
The destination for the intrinsic function’s result is already the target
for the instruction used to implement the intrinsic function (for
example, if L_maca returns a value to a variable declared as type
accum_a)
accum_b b;
int x,y;
...
b = L_maca(b,x,y);
b = L_macb(b,x,y);
accum_a a;
accum_b b;
int x,y;
a = 0;
...
b = L_maca(b,x,y);