Re: [PATCH] RISC-V: Enable overlap-by-pieces in case of fast unaliged access

[Vineet Gupta]

On 11/2/21 1:09 PM, Christoph Müllner wrote:

Without overlap_op_by_pieces we get:
    8e:   00053023                sd      zero,0(a0)
    92:   00052423                sw      zero,8(a0)
    96:   00051623                sh      zero,12(a0)
    9a:   00050723                sb      zero,14(a0)

To generate even the non optimized code above with gcc 11 [1][2], what
do I need to do. Despite -mno-strict-align and trying -mtune={rocket,
sifive-7-series}, I only get the fully unrolled version

You need a tuning struct with slow_unaligned_access == false.
Both, Rocket and Sifive 7, have slow unaligned access set to true.
Mainline you have thead-c906 which would work.

But doesn't -mno-strict-align imply that ?

Thx,
-Vineet