[llvm] r351492 - [HotColdSplit] Allow outlining with live outputs
Vedant Kumar via llvm-commits
llvm-commits at lists.llvm.org
Thu Jan 17 14:36:05 PST 2019
Author: vedantk
Date: Thu Jan 17 14:36:05 2019
New Revision: 351492
URL: http://llvm.org/viewvc/llvm-project?rev=351492&view=rev
Log:
[HotColdSplit] Allow outlining with live outputs
Prior to r348205, extracting code regions with live output values was
disabled because of a miscompilation (PR39433). Lift the restriction as
PR39433 has been addressed.
Tested on LNT+externals, on a run of check-llvm in a stage2 build, and
with a full build of iOS (with hot/cold splitting enabled).
As a drive-by, remove an errant TODO.
Added:
llvm/trunk/test/Transforms/HotColdSplit/split-phis-in-exit-blocks.ll
Modified:
llvm/trunk/lib/Transforms/IPO/HotColdSplitting.cpp
Modified: llvm/trunk/lib/Transforms/IPO/HotColdSplitting.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/HotColdSplitting.cpp?rev=351492&r1=351491&r2=351492&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/HotColdSplitting.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/HotColdSplitting.cpp Thu Jan 17 14:36:05 2019
@@ -252,16 +252,6 @@ Function *HotColdSplitting::extractColdR
/* AllowAlloca */ false,
/* Suffix */ "cold." + std::to_string(Count));
- SetVector<Value *> Inputs, Outputs, Sinks;
- CE.findInputsOutputs(Inputs, Outputs, Sinks);
-
- // Do not extract regions that have live exit variables.
- if (Outputs.size() > 0) {
- LLVM_DEBUG(llvm::dbgs() << "Not outlining; live outputs\n");
- return nullptr;
- }
-
- // TODO: Run MergeBasicBlockIntoOnlyPred on the outlined function.
Function *OrigF = Region[0]->getParent();
if (Function *OutF = CE.extractCodeRegion()) {
User *U = *OutF->user_begin();
Added: llvm/trunk/test/Transforms/HotColdSplit/split-phis-in-exit-blocks.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/HotColdSplit/split-phis-in-exit-blocks.ll?rev=351492&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/HotColdSplit/split-phis-in-exit-blocks.ll (added)
+++ llvm/trunk/test/Transforms/HotColdSplit/split-phis-in-exit-blocks.ll Thu Jan 17 14:36:05 2019
@@ -0,0 +1,68 @@
+; RUN: opt -hotcoldsplit-threshold=0 -hotcoldsplit -S < %s | FileCheck %s
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.14.0"
+
+; CHECK-LABEL: define {{.*}}@pluto(
+; CHECK-NEXT: bb:
+; CHECK-NEXT: %tmp8.ce.loc = alloca i1
+; CHECK-NEXT: switch i8 undef, label %codeRepl [
+; CHECK-NEXT: i8 0, label %bb7
+; CHECK-NEXT: i8 1, label %bb7
+; CHECK-NEXT: ]
+;
+; CHECK: codeRepl:
+; CHECK-NEXT: call void @pluto.cold.1(i1* %tmp8.ce.loc)
+; CHECK-NEXT: %tmp8.ce.reload = load i1, i1* %tmp8.ce.loc
+; CHECK-NEXT: br label %bb7
+;
+; CHECK: bb7:
+; CHECK: %tmp8 = phi i1 [ true, %bb ], [ true, %bb ], [ %tmp8.ce.reload, %codeRepl ]
+; CHECK: ret void
+
+; CHECK-LABEL: define {{.*}}@pluto.cold.1(
+; CHECK: call {{.*}}@sideeffect(i32 1)
+; CHECK: call {{.*}}@sink(
+; CHECK: call {{.*}}@sideeffect(i32 3)
+; CHECK: call {{.*}}@sideeffect(i32 4)
+; CHECK: call {{.*}}@sideeffect(i32 5)
+define void @pluto() {
+bb:
+ switch i8 undef, label %bb1 [
+ i8 0, label %bb7
+ i8 1, label %bb7
+ ]
+
+bb1: ; preds = %bb
+ call void @sideeffect(i32 1)
+ br label %bb2
+
+bb2: ; preds = %bb1
+ call void @sink()
+ br i1 undef, label %bb7, label %bb3
+
+bb3: ; preds = %bb2
+ call void @sideeffect(i32 3)
+ br label %bb4
+
+bb4: ; preds = %bb3
+ call void @sideeffect(i32 4)
+ br i1 undef, label %bb5, label %bb6
+
+bb5: ; preds = %bb4
+ call void @sideeffect(i32 5)
+ br label %bb6
+
+bb6: ; preds = %bb5, %bb4
+ %tmp = phi i1 [ true, %bb5 ], [ false, %bb4 ]
+ call void @sideeffect(i32 6)
+ br label %bb7
+
+bb7: ; preds = %bb6, %bb2, %bb, %bb
+ %tmp8 = phi i1 [ true, %bb ], [ true, %bb ], [ true, %bb2 ], [ %tmp, %bb6 ]
+ ret void
+}
+
+declare void @sink() cold
+
+declare void @sideeffect(i32)
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