llvm/test/CodeGen/R600/unroll.ll
Tom Stellard 01df2fa3c4 R600: Unconditionally unroll loops that contain GEPs with alloca pointers
Implement the getUnrollingPreferences() function for
AMDGPUTargetTransformInfo so that loops that do address calculations
on pointers derived from alloca are unconditionally unrolled.

Unrolling these loops makes it more likely that SROA will be able to
eliminate the allocas, which is a big win for R600 since memory
allocated by alloca (private memory) is really slow.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199916 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-23 18:49:28 +00:00

38 lines
1.1 KiB
LLVM

; RUN: opt -loop-unroll -simplifycfg -sroa %s -S -o - | 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-v16:16:16-v24:32:32-v32:32:32-v48:64:64-v64:64:64-v96:128:128-v128:128:128-v192:256:256-v256:256:256-v512:512:512-v1024:1024:1024-v2048:2048:2048-n32:64"
target triple = "r600--"
; This test contains a simple loop that initializes an array declared in
; private memory. We want to make sure these kinds of loops are always
; unrolled, because private memory is slow.
; CHECK-LABEL: @test
; CHECK-NOT: alloca
; CHECK: store i32 5, i32 addrspace(1)* %out
define void @test(i32 addrspace(1)* %out) {
entry:
%0 = alloca [32 x i32]
br label %loop.header
loop.header:
%counter = phi i32 [0, %entry], [%inc, %loop.inc]
br label %loop.body
loop.body:
%ptr = getelementptr [32 x i32]* %0, i32 0, i32 %counter
store i32 %counter, i32* %ptr
br label %loop.inc
loop.inc:
%inc = add i32 %counter, 1
%1 = icmp sge i32 %counter, 32
br i1 %1, label %exit, label %loop.header
exit:
%2 = getelementptr [32 x i32]* %0, i32 0, i32 5
%3 = load i32* %2
store i32 %3, i32 addrspace(1)* %out
ret void
}