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| author | Sanjoy Das <sanjoy@playingwithpointers.com> | 2015-04-14 03:20:38 +0000 |
|---|---|---|
| committer | Sanjoy Das <sanjoy@playingwithpointers.com> | 2015-04-14 03:20:38 +0000 |
| commit | e178f469655dd0e1a17318e649848e21ed2f9360 (patch) | |
| tree | 819fba9b0780f554a5f8eb83afe0091545258560 /llvm/test/Transforms | |
| parent | a9f1e27a0493892005c1602ffdf76a3a7ff19d73 (diff) | |
| download | bcm5719-llvm-e178f469655dd0e1a17318e649848e21ed2f9360.tar.gz bcm5719-llvm-e178f469655dd0e1a17318e649848e21ed2f9360.zip | |
[LoopUnrollRuntime] Avoid high-cost trip count computation.
Summary:
Runtime unrolling of loops needs to emit an expression to compute the
loop's runtime trip-count. Avoid runtime unrolling if this computation
will be expensive.
Depends on D8993.
Reviewers: atrick
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D8994
llvm-svn: 234846
Diffstat (limited to 'llvm/test/Transforms')
| -rw-r--r-- | llvm/test/Transforms/LoopUnroll/high-cost-trip-count-computation.ll | 27 | ||||
| -rw-r--r-- | llvm/test/Transforms/LoopUnroll/runtime-loop.ll | 2 | ||||
| -rw-r--r-- | llvm/test/Transforms/LoopUnroll/runtime-loop4.ll | 3 |
3 files changed, 31 insertions, 1 deletions
diff --git a/llvm/test/Transforms/LoopUnroll/high-cost-trip-count-computation.ll b/llvm/test/Transforms/LoopUnroll/high-cost-trip-count-computation.ll new file mode 100644 index 00000000000..6b1943f13ba --- /dev/null +++ b/llvm/test/Transforms/LoopUnroll/high-cost-trip-count-computation.ll @@ -0,0 +1,27 @@ +; RUN: opt -S -unroll-runtime -loop-unroll < %s | FileCheck %s + +target datalayout = "e-p:64:64:64-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-s0:64:64-f80:128:128-n8:16:32:64-S128" + +;; Check that we don't emit expensive instructions to compute trip +;; counts when unrolling loops. + +define i32 @test(i64 %v12, i8* %array, i64* %loc) { +; CHECK-LABEL: @test( +; CHECK-NOT: udiv +entry: + %step = load i64, i64* %loc, !range !0 + br label %loop + +loop: ; preds = %entry, %loop + %k.015 = phi i64 [ %v15, %loop ], [ %v12, %entry ] + %v14 = getelementptr inbounds i8, i8* %array, i64 %k.015 + store i8 0, i8* %v14 + %v15 = add nuw nsw i64 %k.015, %step + %v16 = icmp slt i64 %v15, 8193 + br i1 %v16, label %loop, label %loopexit + +loopexit: ; preds = %loop + ret i32 0 +} + +!0 = !{i64 1, i64 100} diff --git a/llvm/test/Transforms/LoopUnroll/runtime-loop.ll b/llvm/test/Transforms/LoopUnroll/runtime-loop.ll index 9e78edfb25e..fea15b65d5a 100644 --- a/llvm/test/Transforms/LoopUnroll/runtime-loop.ll +++ b/llvm/test/Transforms/LoopUnroll/runtime-loop.ll @@ -1,5 +1,7 @@ ; RUN: opt < %s -S -loop-unroll -unroll-runtime=true | FileCheck %s +target datalayout = "e-p:64:64:64-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-s0:64:64-f80:128:128-n8:16:32:64-S128" + ; Tests for unrolling loops with run-time trip counts ; CHECK: %xtraiter = and i32 %n diff --git a/llvm/test/Transforms/LoopUnroll/runtime-loop4.ll b/llvm/test/Transforms/LoopUnroll/runtime-loop4.ll index 9be0ffd23d3..5014c739e4c 100644 --- a/llvm/test/Transforms/LoopUnroll/runtime-loop4.ll +++ b/llvm/test/Transforms/LoopUnroll/runtime-loop4.ll @@ -20,7 +20,8 @@ loop1: br label %loop2.header loop2.header: - br label %loop2 + %e = icmp uge i32 %iter, 1 + br i1 %e, label %loop2, label %exit2 loop2: %iv2 = phi i32 [ 0, %loop2.header ], [ %inc2, %loop2 ] |
