llvm-6502/test/CodeGen/Thumb2/2010-04-15-DynAllocBug.ll
Jim Grosbach 65482b1bb8 Re-apply r112883:
"For ARM stack frames that utilize variable sized objects and have either
large local stack areas or require dynamic stack realignment, allocate a
base register via which to access the local frame. This allows efficient
access to frame indices not accessible via the FP (either due to being out
of range or due to dynamic realignment) or the SP (due to variable sized
object allocation). In particular, this greatly improves efficiency of access
to spill slots in Thumb functions which contain VLAs."

r112986 fixed a latent bug exposed by the above.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112989 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-03 18:37:12 +00:00

19 lines
490 B
LLVM

; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a8 -O3 | FileCheck %s
; rdar://7493908
; Make sure the result of the first dynamic_alloc isn't copied back to sp more
; than once. We'll deal with poor codegen later.
define void @t() nounwind ssp {
entry:
; CHECK: t:
%size = mul i32 8, 2
; CHECK: subs r0, #16
; CHECK: mov sp, r0
%vla_a = alloca i8, i32 %size, align 8
; CHECK: subs r0, #16
; CHECK: mov sp, r0
%vla_b = alloca i8, i32 %size, align 8
unreachable
}