ARM64: Investigate why more stack space is allocated than needed and why they are not aligned #37429
Description
This was brought to the attention by @TamarChristinaArm in #37139 (comment). For a method that takes 2 Vector64<> parameters, there are couple of problems:
- We allocate stack space of 48 bytes although we just want to store 16 bytes.
- The 16 bytes that is stored are not aligned properly. If they are aligned properly, we can convert it tp
stpinstead.
Here is the sample code:
G_M35607_IG01:
A9BD7BFD stp fp, lr, [sp,#-48]!
910003FD mov fp, sp
FD0017A0 str d0, [fp,#40]
FD000FA1 str d1, [fp,#24]
;; bbWeight=1 PerfScore 3.50
G_M35607_IG02:
FD4017B0 ldr d16, [fp,#40]
FD400FB1 ldr d17, [fp,#24]
0EB01E10 mov v16.8b, v16.8b
Here is the assembly code for reference: Create_after.txt