ccd819ad94
[AVR] Implement stacksave/stackrestore by expanding (PR31342)
...
Summary:
Authored by Florian Zeitz.
This implements the missing stacksave/stackrestore intrinsics via expansion.
Output of `llc -O0 -march=avr ~/devel/llvm/test/CodeGen/Generic/stacksave-restore.ll` for sanity checking (comments mine):
```
.text
.file ".../llvm/test/CodeGen/Generic/stacksave-restore.ll"
.globl test
.p2align 1
.type test,@function
test: ; @test
; BB#0:
push r28
push r29
in r28, 61
in r29, 62
sbiw r28, 4
in r0, 63
cli
out 62, r29
out 63, r0
out 61, r28
in r18, 61
in r19, 62
mov r20, r22
mov r21, r23
in r30, 61
in r31, 62
lsl r22
rol r23
lsl r22
rol r23
in r26, 61
in r27, 62
sub r26, r22
sbc r27, r23
andi r26, 252
in r0, 63
cli
out 62, r27
out 63, r0
out 61, r26
in r0, 63
cli
out 62, r31
out 63, r0
out 61, r30
in r30, 61
in r31, 62
sub r30, r22
sbc r31, r23
andi r30, 252
in r0, 63
cli
out 62, r31
out 63, r0
out 61, r30
std Y+3, r24 ; 2-byte Folded Spill
std Y+4, r25 ; 2-byte Folded Spill
mov r24, r26
mov r25, r27
in r0, 63
cli
out 62, r19
out 63, r0
out 61, r18
std Y+1, r20 ; 2-byte Folded Spill
std Y+2, r21 ; 2-byte Folded Spill
adiw r28, 4
in r0, 63
cli
out 62, r29
out 63, r0
out 61, r28
pop r29
pop r28
ret
.Lfunc_end0:
.size test, .Lfunc_end0-test
```
Reviewers: dylanmckay
Reviewed By: dylanmckay
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29553
llvm-svn: 294146
2017-02-05 21:35:45 +00:00
Dylan McKay