Messages in this thread | | | Subject | Re: gcc -O3 and register usage | From | Felipe Alfaro Solana <> | Date | Tue, 19 Aug 2003 12:17:19 +0200 |
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On Tue, 2003-08-19 at 02:15, J.A. Magallon wrote:
> Does this mean that since PentiumPro gcc has one other register (%dl) > available, and it uses it only at -O3 ?
AFAIK, the EDX 32-bit register is splitted in two 16-bit halves, being the least significant half called DX which, at the sime time, is splitted in two 8-bit halves of which the most significant is called DH, while the least significant is called DL.
So, DL is not a new register, but the least significant 8-bits from the EDX CPU register.
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