llvm-project

Commit Graph

Author	SHA1	Message	Date
Evan Cheng	fd81c73cde	Optimize some 64-bit multiplication by constants into two lea's or one lea + shl since imulq is slow (latency 5). e.g. x * 40 => shlq $3, %rdi leaq (%rdi,%rdi,4), %rax This has the added benefit of allowing more multiply to be folded into addressing mode. e.g. a * 24 + b => leaq (%rdi,%rdi,2), %rax leaq (%rsi,%rax,8), %rax llvm-svn: 67917	2009-03-28 05:57:29 +00:00

Author

SHA1

Message

Date

Evan Cheng

fd81c73cde

Optimize some 64-bit multiplication by constants into two lea's or one lea + shl since imulq is slow (latency 5). e.g.

x * 40
=>
shlq    $3, %rdi
leaq    (%rdi,%rdi,4), %rax

This has the added benefit of allowing more multiply to be folded into addressing mode. e.g.
a * 24 + b
=>
leaq    (%rdi,%rdi,2), %rax
leaq    (%rsi,%rax,8), %rax

llvm-svn: 67917

2009-03-28 05:57:29 +00:00

1 Commits