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| author | Anton Korobeynikov <asl@math.spbu.ru> | 2009-11-24 00:44:37 +0000 |
|---|---|---|
| committer | Anton Korobeynikov <asl@math.spbu.ru> | 2009-11-24 00:44:37 +0000 |
| commit | 5cdc3a949af0cef7f2163f8a7acbf3049c226321 (patch) | |
| tree | 6cbd9b033b162075d09d6815be1c15f65f1bd468 /test/CodeGen | |
| parent | 6935efcb667bcd4dd3a00bbd420461e1fadba73a (diff) | |
| download | llvm-5cdc3a949af0cef7f2163f8a7acbf3049c226321.tar.gz llvm-5cdc3a949af0cef7f2163f8a7acbf3049c226321.tar.bz2 llvm-5cdc3a949af0cef7f2163f8a7acbf3049c226321.tar.xz | |
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
Diffstat (limited to 'test/CodeGen')
| -rw-r--r-- | test/CodeGen/ARM/movt-movw-global.ll | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/test/CodeGen/ARM/movt-movw-global.ll b/test/CodeGen/ARM/movt-movw-global.ll new file mode 100644 index 0000000000..886ff3fea7 --- /dev/null +++ b/test/CodeGen/ARM/movt-movw-global.ll @@ -0,0 +1,20 @@ +; 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 +} |