llvm-6502/test/CodeGen/ARM/movt-movw-global.ll
Anton Korobeynikov 5cdc3a949a Materialize global addresses via movt/movw pair, this is always better
than doing the same via constpool:
1. Load from constpool costs 3 cycles on A9, movt/movw pair - just 2.
2. Load from constpool might stall up to 300 cycles due to cache miss.
3. Movt/movw does not use load/store unit.
4. Less constpool entries => better compiler performance.

This is only enabled on ELF systems, since darwin does not have needed
relocations (yet).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89720 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-24 00:44:37 +00:00

21 lines
611 B
LLVM

; RUN: llc < %s | FileCheck %s
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64"
target triple = "armv7-eabi"
@foo = common global i32 0 ; <i32*> [#uses=1]
define arm_aapcs_vfpcc i32* @bar1() nounwind readnone {
entry:
; CHECK: movw r0, :lower16:foo
; CHECK-NEXT: movt r0, :upper16:foo
ret i32* @foo
}
define arm_aapcs_vfpcc void @bar2(i32 %baz) nounwind {
entry:
; CHECK: movw r1, :lower16:foo
; CHECK-NEXT: movt r1, :upper16:foo
store i32 %baz, i32* @foo, align 4
ret void
}