[PATCH] D67752: [ARM] Loop unrolling preferences for LOB cores

Thu Sep 26 01:50:11 PDT 2019

SjoerdMeijer added a comment.

The added tests check exactly what's being changed/added here, so that's excellent.
I was just wondering if it would be good if we also add a more end-to-end/unit `llc` test, that shows actual loloop creation for these cases? That is, if these tests are not already there. I had only a very quick look, and am not sure, but you'll probably know.

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Comment at: test/Transforms/LoopUnroll/ARM/loop-unrolling.ll:1
-; RUN: opt -mtriple=armv7 -mcpu=cortex-a57 -loop-unroll -S %s -o - | FileCheck %s --check-prefix=CHECK-UNROLL-A
-; RUN: opt -mtriple=thumbv7 -mcpu=cortex-a57 -loop-unroll -S %s -o - | FileCheck %s --check-prefix=CHECK-UNROLL-A
-; RUN: opt -mtriple=thumbv7 -mcpu=cortex-a72 -loop-unroll -S %s -o - | FileCheck %s --check-prefix=CHECK-UNROLL-A
-; RUN: opt -mtriple=thumbv8m -mcpu=cortex-m23 -loop-unroll -S %s -o - | FileCheck %s --check-prefix=CHECK-UNROLL-T1
-; RUN: opt -mtriple=thumbv8m.main -mcpu=cortex-m33 -loop-unroll -S %s -o - | FileCheck %s --check-prefix=CHECK-UNROLL-T2
-; RUN: opt -mtriple=thumbv7em -mcpu=cortex-m7 -loop-unroll -S %s -o - | FileCheck %s --check-prefix=CHECK-UNROLL-T2
+; RUN: opt -mtriple=armv7 -mcpu=cortex-a57 -loop-unroll -S %s -o - | FileCheck %s --check-prefix=CHECK-UNROLL-A --check-prefix=CHECK
+; RUN: opt -mtriple=thumbv7 -mcpu=cortex-a57 -loop-unroll -S %s -o - | FileCheck %s --check-prefix=CHECK-UNROLL-A --check-prefix=CHECK
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nit:  `--check-prefixes=CHECK-UNROLL-A,CHECK` is shorter

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Comment at: test/Transforms/LoopUnroll/ARM/loop-unrolling.ll:48

+; CHECK-UNROLL-LOB: [[IV0:%[a-z.0-9]+]] = phi i32 [ 0, %entry ], [ [[IV16:%[a-z.0-9]+]], %for.body ]
+; CHECK-UNROLL-LOB: [[IV1:%[a-z.0-9]+]] = add nuw nsw i32 [[IV0]], 1
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nit: this whole block looks exactly the same as CHECK-UNROLL-T2, so could be shared.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D67752/new/

https://reviews.llvm.org/D67752