On 04/11/2016 06:58 AM, Thomas Hanson wrote:
Ah, true.
On 9 April 2016 at 09:57, Richard Henderson <r...@twiddle.net
<mailto:r...@twiddle.net>> wrote:
On 04/08/2016 05:29 PM, Thomas Hanson wrote:
Looking at tcg_out_tlb_load():
If I'm reading the pseudo-assembler of the function names
correctly, it looks
like in the i386 code we're already masking the address being
checked:
tgen_arithi(s, ARITH_AND + trexw, r1, TARGET_PAGE_MASK |
(aligned ? s_mask
: 0), 0);
where TARGET_PAGE_MASK is a simple all-1's mask in the
appropriate upper bits.
Can we just poke some 0's into that mask in the tag locations?
No, because we'd no longer have a sign-extended 32-bit value, as
fits in that immediate operand field. To load the constant you're
asking for, we'd need a 64-bit move insn and another register.
r~
[Sorry for the previous top post(s). I've switched email clients...]
So, is the consensus that it's not worth adding an instruction to the
fast path to avoid kicking out TLB entries with non-matching tags?
Or is this still under consideration?
