On 9/12/23 13:09, Jivan Hakobyan via Gcc-patches wrote:
In the case when we have C code like this
int foo (int a) {
return 100 & ~a;
}
GCC generates the following instruction sequence
foo:
not a0,a0
andia0,a0,100
ret
This patch replaces that with this sequence
In the case when we have C code like this
int foo (int a) {
return 100 & ~a;
}
GCC generates the following instruction sequence
foo:
not a0,a0
andia0,a0,100
ret
This patch replaces that with this sequence
foo:
li a5,100
andn a0,a5,a0
ret
The profitabili
On 9/11/23 13:16, Andrew Waterman via Gcc-patches wrote:
Note this is a size-speed tradeoff, as the Zcb extension has a
16-bit-wide C.NOT instruction. Might want to suppress this
optimization when Zcb is present and the function is being optimize > for size.
Yea, let's gate this on !optimize
Note this is a size-speed tradeoff, as the Zcb extension has a
16-bit-wide C.NOT instruction. Might want to suppress this
optimization when Zcb is present and the function is being optimized
for size.
On Mon, Sep 11, 2023 at 9:52 AM Jivan Hakobyan via Gcc-patches
wrote:
>
> In the case when we
In the case when we have C code like this
int foo (int a) {
return 100 & ~a;
}
GCC generates the following instruction sequence
foo:
not a0,a0
andia0,a0,100
ret
This patch replaces that with this sequence
foo:
li a5,100
andn a0,a5,a0
ret
The profitabili
