Shaun Jackman wrote:
The following code snippet produces code that loads a register, r5,
from memory, but never uses the value.
You can report things like this into our bugzilla database, marking them
as enhancement requests. We don't keep track of issues reported to the
gcc list.
I took a quick look. The underlying problem is that the arm.md file has
an iordi3 pattern, which gets split late, preventing us from recognizing
some optimization chances here. If I just disable the iordi3 pattern,
then I get much better code.
ldr r0, .L3
mov r1, r0, asr #31
orr r1, r1, #34603008
@ lr needed for prologue
bx lr
Disabling this pattern may result in worse code for other testcases
though. It was presumably added for a reason.
--
Jim Wilson, GNU Tools Support, http://www.specifix.com
