1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-10-25 22:12:57 +02:00
llvm-mirror/test/Transforms/LoopUnroll/high-cost-trip-count-computation.ll
Sanjoy Das b9907c45f6 [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
2015-04-14 03:20:38 +00:00

28 lines
906 B
LLVM

; 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}