[DSE,MSSA] Add debug counter.

Can be used like
-debug-counter=dse-memoryssa-skip=10,dse-memoryssa-counter-count=20

Reviewers: dmgreen, rnk, efriedma, bryant, asbirlea

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D72147
This commit is contained in:
Florian Hahn 2020-02-21 16:55:18 +00:00
parent 9fff6e823c
commit 134bab7cd5
2 changed files with 91 additions and 0 deletions
llvm
lib/Transforms/Scalar
test/Transforms/DeadStoreElimination/MSSA

View File

@ -57,6 +57,7 @@
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/DebugCounter.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
@ -80,6 +81,9 @@ STATISTIC(NumFastOther, "Number of other instrs removed");
STATISTIC(NumCompletePartials, "Number of stores dead by later partials");
STATISTIC(NumModifiedStores, "Number of stores modified");
DEBUG_COUNTER(MemorySSACounter, "dse-memoryssa",
"Controls which MemoryDefs are eliminated.");
static cl::opt<bool>
EnablePartialOverwriteTracking("enable-dse-partial-overwrite-tracking",
cl::init(true), cl::Hidden,
@ -1795,6 +1799,9 @@ bool eliminateDeadStoresMemorySSA(Function &F, AliasAnalysis &AA,
break;
}
if (!DebugCounter::shouldExecute(MemorySSACounter))
break;
// Check if NI overwrites SI.
int64_t InstWriteOffset, DepWriteOffset;
InstOverlapIntervalsTy IOL;

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@ -0,0 +1,84 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; Eliminates store to %R in the entry block.
; RUN: opt < %s -basicaa -dse -enable-dse-memoryssa -debug-counter=dse-memoryssa-skip=0,dse-memoryssa-count=1 -S | FileCheck --check-prefix=SKIP0-COUNT1 %s
; Eliminates store to %P in the entry block.
; RUN: opt < %s -basicaa -dse -enable-dse-memoryssa -debug-counter=dse-memoryssa-skip=1,dse-memoryssa-count=1 -S | FileCheck --check-prefix=SKIP1-COUNT1 %s
; Eliminates both stores in the entry block.
; RUN: opt < %s -basicaa -dse -enable-dse-memoryssa -debug-counter=dse-memoryssa-skip=0,dse-memoryssa-count=2 -S | FileCheck --check-prefix=SKIP0-COUNT2 %s
; Eliminates no stores.
; RUN: opt < %s -basicaa -dse -enable-dse-memoryssa -debug-counter=dse-memoryssa-skip=2,dse-memoryssa-count=1 -S | FileCheck --check-prefix=SKIP2-COUNT1 %s
target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
define void @test(i32* noalias %P, i32* noalias %Q, i32* noalias %R) {
; SKIP0-COUNT1-LABEL: @test(
; SKIP0-COUNT1-NEXT: store i32 1, i32* [[P:%.*]]
; SKIP0-COUNT1-NEXT: br i1 true, label [[BB1:%.*]], label [[BB2:%.*]]
; SKIP0-COUNT1: bb1:
; SKIP0-COUNT1-NEXT: br label [[BB3:%.*]]
; SKIP0-COUNT1: bb2:
; SKIP0-COUNT1-NEXT: br label [[BB3]]
; SKIP0-COUNT1: bb3:
; SKIP0-COUNT1-NEXT: store i32 0, i32* [[Q:%.*]]
; SKIP0-COUNT1-NEXT: store i32 0, i32* [[R:%.*]]
; SKIP0-COUNT1-NEXT: store i32 0, i32* [[P]]
; SKIP0-COUNT1-NEXT: ret void
;
; SKIP1-COUNT1-LABEL: @test(
; SKIP1-COUNT1-NEXT: store i32 1, i32* [[R:%.*]]
; SKIP1-COUNT1-NEXT: br i1 true, label [[BB1:%.*]], label [[BB2:%.*]]
; SKIP1-COUNT1: bb1:
; SKIP1-COUNT1-NEXT: br label [[BB3:%.*]]
; SKIP1-COUNT1: bb2:
; SKIP1-COUNT1-NEXT: br label [[BB3]]
; SKIP1-COUNT1: bb3:
; SKIP1-COUNT1-NEXT: store i32 0, i32* [[Q:%.*]]
; SKIP1-COUNT1-NEXT: store i32 0, i32* [[R]]
; SKIP1-COUNT1-NEXT: store i32 0, i32* [[P:%.*]]
; SKIP1-COUNT1-NEXT: ret void
;
; SKIP0-COUNT2-LABEL: @test(
; SKIP0-COUNT2-NEXT: br i1 true, label [[BB1:%.*]], label [[BB2:%.*]]
; SKIP0-COUNT2: bb1:
; SKIP0-COUNT2-NEXT: br label [[BB3:%.*]]
; SKIP0-COUNT2: bb2:
; SKIP0-COUNT2-NEXT: br label [[BB3]]
; SKIP0-COUNT2: bb3:
; SKIP0-COUNT2-NEXT: store i32 0, i32* [[Q:%.*]]
; SKIP0-COUNT2-NEXT: store i32 0, i32* [[R:%.*]]
; SKIP0-COUNT2-NEXT: store i32 0, i32* [[P:%.*]]
; SKIP0-COUNT2-NEXT: ret void
;
; SKIP2-COUNT1-LABEL: @test(
; SKIP2-COUNT1-NEXT: store i32 1, i32* [[P:%.*]]
; SKIP2-COUNT1-NEXT: store i32 1, i32* [[R:%.*]]
; SKIP2-COUNT1-NEXT: br i1 true, label [[BB1:%.*]], label [[BB2:%.*]]
; SKIP2-COUNT1: bb1:
; SKIP2-COUNT1-NEXT: br label [[BB3:%.*]]
; SKIP2-COUNT1: bb2:
; SKIP2-COUNT1-NEXT: br label [[BB3]]
; SKIP2-COUNT1: bb3:
; SKIP2-COUNT1-NEXT: store i32 0, i32* [[Q:%.*]]
; SKIP2-COUNT1-NEXT: store i32 0, i32* [[R]]
; SKIP2-COUNT1-NEXT: store i32 0, i32* [[P]]
; SKIP2-COUNT1-NEXT: ret void
;
store i32 1, i32* %P
store i32 1, i32* %R
br i1 true, label %bb1, label %bb2
bb1:
br label %bb3
bb2:
br label %bb3
bb3:
store i32 0, i32* %Q
store i32 0, i32* %R
store i32 0, i32* %P
ret void
}