RE: [X86 PATCH] Split lea into shorter left shift by 2 or 3 bits with -Oz.

2023-10-05 Thread Roger Sayle
Hi Uros, Very many thanks for the speedy reviews. Uros Bizjak wrote: > On Thu, Oct 5, 2023 at 11:06 AM Roger Sayle > wrote: > > > > > > This patch avoids long lea instructions for performing x<<2 and x<<3 > > by splitting them into shorter sal and move (or xchg instructions). > > Because this i

Re: [X86 PATCH] Split lea into shorter left shift by 2 or 3 bits with -Oz.

2023-10-05 Thread Uros Bizjak
On Thu, Oct 5, 2023 at 11:06 AM Roger Sayle wrote: > > > This patch avoids long lea instructions for performing x<<2 and x<<3 > by splitting them into shorter sal and move (or xchg instructions). > Because this increases the number of instructions, but reduces the > total size, its suitable for -O

[X86 PATCH] Split lea into shorter left shift by 2 or 3 bits with -Oz.

2023-10-05 Thread Roger Sayle
This patch avoids long lea instructions for performing x<<2 and x<<3 by splitting them into shorter sal and move (or xchg instructions). Because this increases the number of instructions, but reduces the total size, its suitable for -Oz (but not -Os). The impact can be seen in the new test case: