TTI: Improve default costs for addrspacecast

For some reason multiple places need to do this, and the variant the
loop unroller and inliner use was not handling it.

Also, introduce a new wrapper to be slightly more precise, since on
AMDGPU some addrspacecasts are free, but not no-ops.

llvm-svn: 362436

1 files changed, 77 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopUnroll/AMDGPU/unroll-cost-addrspacecast.ll b/llvm/test/Transforms/LoopUnroll/AMDGPU/unroll-cost-addrspacecast.ll
new file mode 100644
index 00000000000..761aa077606
--- /dev/null
+++ b/llvm/test/Transforms/LoopUnroll/AMDGPU/unroll-cost-addrspacecast.ll
@@ -0,0 +1,77 @@
+; RUN: opt -S -mtriple=amdgcn-unknown-amdhsa -mcpu=hawaii -loop-unroll -unroll-threshold=75 -unroll-peel-count=0 -unroll-allow-partial=false -unroll-max-iteration-count-to-analyze=16 < %s | FileCheck %s
+
+; CHECK-LABEL: @test_func_addrspacecast_cost_noop(
+; CHECK-NOT: br i1
+define amdgpu_kernel void @test_func_addrspacecast_cost_noop(float addrspace(1)* noalias nocapture %out, float addrspace(1)* noalias nocapture %in) #0 {
+entry:
+  br label %for.body
+
+for.body:
+  %indvars.iv = phi i32 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
+  %sum.02 = phi float [ %fmul, %for.body ], [ 0.0, %entry ]
+  %arrayidx.in = getelementptr inbounds float, float addrspace(1)* %in, i32 %indvars.iv
+  %arrayidx.out = getelementptr inbounds float, float addrspace(1)* %out, i32 %indvars.iv
+  %cast.in = addrspacecast float addrspace(1)* %arrayidx.in to float*
+  %cast.out = addrspacecast float addrspace(1)* %arrayidx.out to float*
+  %load = load float, float* %cast.in
+  %fmul = fmul float %load, %sum.02
+  store float %fmul, float* %cast.out
+  %indvars.iv.next = add i32 %indvars.iv, 1
+  %exitcond = icmp eq i32 %indvars.iv.next, 16
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:
+  ret void
+}
+
+; Free, but not a no-op
+; CHECK-LABEL: @test_func_addrspacecast_cost_free(
+; CHECK-NOT: br i1
+define amdgpu_kernel void @test_func_addrspacecast_cost_free(float* noalias nocapture %out, float* noalias nocapture %in) #0 {
+entry:
+  br label %for.body
+
+for.body:
+  %indvars.iv = phi i32 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
+  %sum.02 = phi float [ %fmul, %for.body ], [ 0.0, %entry ]
+  %arrayidx.in = getelementptr inbounds float, float* %in, i32 %indvars.iv
+  %arrayidx.out = getelementptr inbounds float, float* %out, i32 %indvars.iv
+  %cast.in = addrspacecast float* %arrayidx.in to float addrspace(3)*
+  %cast.out = addrspacecast float* %arrayidx.out to float addrspace(3)*
+  %load = load float, float addrspace(3)* %cast.in
+  %fmul = fmul float %load, %sum.02
+  store float %fmul, float addrspace(3)* %cast.out
+  %indvars.iv.next = add i32 %indvars.iv, 1
+  %exitcond = icmp eq i32 %indvars.iv.next, 16
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:
+  ret void
+}
+
+; CHECK-LABEL: @test_func_addrspacecast_cost_nonfree(
+; CHECK: br i1 %exitcond
+define amdgpu_kernel void @test_func_addrspacecast_cost_nonfree(float addrspace(3)* noalias nocapture %out, float addrspace(3)* noalias nocapture %in) #0 {
+entry:
+  br label %for.body
+
+for.body:
+  %indvars.iv = phi i32 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
+  %sum.02 = phi float [ %fmul, %for.body ], [ 0.0, %entry ]
+  %arrayidx.in = getelementptr inbounds float, float addrspace(3)* %in, i32 %indvars.iv
+  %arrayidx.out = getelementptr inbounds float, float addrspace(3)* %out, i32 %indvars.iv
+  %cast.in = addrspacecast float addrspace(3)* %arrayidx.in to float*
+  %cast.out = addrspacecast float addrspace(3)* %arrayidx.out to float*
+  %load = load float, float* %cast.in
+  %fmul = fmul float %load, %sum.02
+  store float %fmul, float* %cast.out
+  %indvars.iv.next = add i32 %indvars.iv, 1
+  %exitcond = icmp eq i32 %indvars.iv.next, 16
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:
+  ret void
+}
+
+attributes #0 = { nounwind }
+attributes #1 = { nounwind readnone speculatable }