mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-22 18:54:02 +01:00
c5e9c8b1df
Summary: Current implementation of getLoopEstimatedTripCount returns 1 iteration less than it should. The reason is that in bottom tested loop first iteration is executed before first back branch is taken. For example for loop with !{!"branch_weights", i32 1 // taken, i32 1 // exit} metadata getLoopEstimatedTripCount gives 1 while actual number of iterations is 2.
Reviewers: Ayal, fhahn
Reviewed By: Ayal
Subscribers: mgorny, hiraditya, zzheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71990
44 lines
1.2 KiB
LLVM
44 lines
1.2 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
|
|
; RUN: opt < %s -S -loop-unroll -loop-unroll -verify-dom-info -debug-only=loop-unroll -unroll-peel-max-count=7 2>&1 | FileCheck %s
|
|
; REQUIRES: asserts
|
|
|
|
declare void @f1()
|
|
declare void @f2()
|
|
|
|
; Check that we can peel off iterations that make conditions true.
|
|
; The second invocation of loop-unroll will do profile based peeling of
|
|
; remained iterations.
|
|
define void @test1(i32 %k) !prof !4 {
|
|
; CHECK: Loop Unroll: F[test1] Loop %for.body
|
|
; CHECK: PEELING loop %for.body with iteration count 2!
|
|
; CHECK: PEELING loop %for.body with iteration count 5!
|
|
; CHECK: llvm.loop.unroll.disable
|
|
for.body.lr.ph:
|
|
br label %for.body
|
|
|
|
for.body:
|
|
%i.05 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.inc ]
|
|
%cmp1 = icmp ult i32 %i.05, 2
|
|
br i1 %cmp1, label %if.then, label %if.else
|
|
|
|
if.then:
|
|
call void @f1()
|
|
br label %for.inc
|
|
|
|
if.else:
|
|
call void @f2()
|
|
br label %for.inc
|
|
|
|
for.inc:
|
|
%inc = add nsw i32 %i.05, 1
|
|
%cmp = icmp slt i32 %inc, %k
|
|
br i1 %cmp, label %for.body, label %for.end, !llvm.loop !1, !prof !2
|
|
|
|
for.end:
|
|
ret void
|
|
}
|
|
|
|
!1 = distinct !{!1}
|
|
!2 = !{!"branch_weights", i32 6, i32 1}
|
|
!4 = !{!"function_entry_count", i64 1}
|