From 2aed6ca1d33468f7e6f8509213a1b9dcd8026ec1 Mon Sep 17 00:00:00 2001 From: Matt Arsenault Date: Sat, 19 Dec 2015 01:46:41 +0000 Subject: AMDGPU: Switch barrier intrinsics to using convergent noduplicate prevents unrolling of small loops that happen to have barriers in them. If a loop has a barrier in it, it is OK to duplicate it for the unroll. llvm-svn: 256075 --- .../Transforms/LoopUnroll/AMDGPU/lit.local.cfg | 3 ++ .../Transforms/LoopUnroll/AMDGPU/unroll-barrier.ll | 33 ++++++++++++++++++++++ 2 files changed, 36 insertions(+) create mode 100644 llvm/test/Transforms/LoopUnroll/AMDGPU/lit.local.cfg create mode 100644 llvm/test/Transforms/LoopUnroll/AMDGPU/unroll-barrier.ll (limited to 'llvm/test/Transforms/LoopUnroll') diff --git a/llvm/test/Transforms/LoopUnroll/AMDGPU/lit.local.cfg b/llvm/test/Transforms/LoopUnroll/AMDGPU/lit.local.cfg new file mode 100644 index 00000000000..6baccf05fff --- /dev/null +++ b/llvm/test/Transforms/LoopUnroll/AMDGPU/lit.local.cfg @@ -0,0 +1,3 @@ +if not 'AMDGPU' in config.root.targets: + config.unsupported = True + diff --git a/llvm/test/Transforms/LoopUnroll/AMDGPU/unroll-barrier.ll b/llvm/test/Transforms/LoopUnroll/AMDGPU/unroll-barrier.ll new file mode 100644 index 00000000000..3cbb70274da --- /dev/null +++ b/llvm/test/Transforms/LoopUnroll/AMDGPU/unroll-barrier.ll @@ -0,0 +1,33 @@ +; RUN: opt -mtriple=amdgcn-unknown-amdhsa -mcpu=hawaii -loop-unroll -S < %s | FileCheck %s + +; CHECK-LABEL: @test_unroll_convergent_barrier( +; CHECK: call void @llvm.AMDGPU.barrier.global() +; CHECK: call void @llvm.AMDGPU.barrier.global() +; CHECK: call void @llvm.AMDGPU.barrier.global() +; CHECK: call void @llvm.AMDGPU.barrier.global() +; CHECK-NOT: br +define void @test_unroll_convergent_barrier(i32 addrspace(1)* noalias nocapture %out, i32 addrspace(1)* noalias nocapture %in) #0 { +entry: + br label %for.body + +for.body: ; preds = %for.body, %entry + %indvars.iv = phi i32 [ %indvars.iv.next, %for.body ], [ 0, %entry ] + %sum.02 = phi i32 [ %add, %for.body ], [ 0, %entry ] + %arrayidx.in = getelementptr inbounds i32, i32 addrspace(1)* %in, i32 %indvars.iv + %arrayidx.out = getelementptr inbounds i32, i32 addrspace(1)* %out, i32 %indvars.iv + %load = load i32, i32 addrspace(1)* %arrayidx.in + call void @llvm.AMDGPU.barrier.global() #1 + %add = add i32 %load, %sum.02 + store i32 %add, i32 addrspace(1)* %arrayidx.out + %indvars.iv.next = add i32 %indvars.iv, 1 + %exitcond = icmp eq i32 %indvars.iv.next, 4 + br i1 %exitcond, label %for.end, label %for.body + +for.end: ; preds = %for.body, %entry + ret void +} + +declare void @llvm.AMDGPU.barrier.global() #1 + +attributes #0 = { nounwind } +attributes #1 = { nounwind convergent } -- cgit v1.2.3