[CodeExtractor] Emit lifetime markers around reloads of outputs

CodeExtractor permits extracting a region of blocks from a function even
when values defined within the region are used outside of it.

This is typically done by creating an alloca in the original function
and reloading the alloca after a call to the extracted function.

Wrap the reload in lifetime start/end markers to promote stack coloring.

Suggested by Sergei Kachkov!

Differential Revision: https://reviews.llvm.org/D56045

llvm-svn: 351621
diff --git a/llvm/test/Transforms/HotColdSplit/duplicate-phi-preds-crash.ll b/llvm/test/Transforms/HotColdSplit/duplicate-phi-preds-crash.ll
index da3468a..fa68300 100644
--- a/llvm/test/Transforms/HotColdSplit/duplicate-phi-preds-crash.ll
+++ b/llvm/test/Transforms/HotColdSplit/duplicate-phi-preds-crash.ll
@@ -15,7 +15,7 @@
 ; CHECK: call {{.*}}@sideeffect(
 ; CHECK: call {{.*}}@realloc(
 ; CHECK-LABEL: codeRepl:
-; CHECK-NEXT: call {{.*}}@realloc2.cold.1(i64 %size, i8* %ptr, i8** %retval.0.ce.loc)
+; CHECK: call {{.*}}@realloc2.cold.1(i64 %size, i8* %ptr, i8** %retval.0.ce.loc)
 ; CHECK-LABEL: cleanup:
 ; CHECK-NEXT: phi i8* [ null, %if.then ], [ %call, %if.end ], [ %retval.0.ce.reload, %codeRepl ]
 define i8* @realloc2(i8* %ptr, i64 %size) {
diff --git a/llvm/test/Transforms/HotColdSplit/lifetime-markers-on-inputs.ll b/llvm/test/Transforms/HotColdSplit/lifetime-markers-on-inputs.ll
index d46ef78..e80e2b9 100644
--- a/llvm/test/Transforms/HotColdSplit/lifetime-markers-on-inputs.ll
+++ b/llvm/test/Transforms/HotColdSplit/lifetime-markers-on-inputs.ll
@@ -30,13 +30,13 @@
 
 ; CHECK-LABEL: codeRepl:
 ; CHECK: [[local1_cast:%.*]] = bitcast i256* %local1 to i8*
-; CHECK: call void @llvm.lifetime.start.p0i8(i64 -1, i8* [[local1_cast]])
-; CHECK: [[local2_cast:%.*]] = bitcast i256* %local2 to i8*
-; CHECK: call void @llvm.lifetime.start.p0i8(i64 -1, i8* [[local2_cast]])
-; CHECK: call i1 @foo.cold.1(i8* %local1_cast, i8* %local2_cast)
-; CHECK: call void @llvm.lifetime.end.p0i8(i64 -1, i8* [[local2_cast]])
-; CHECK: call void @llvm.lifetime.end.p0i8(i64 -1, i8* [[local1_cast]])
-; CHECK: br i1
+; CHECK-NEXT: call void @llvm.lifetime.start.p0i8(i64 -1, i8* [[local1_cast]])
+; CHECK-NEXT: [[local2_cast:%.*]] = bitcast i256* %local2 to i8*
+; CHECK-NEXT: call void @llvm.lifetime.start.p0i8(i64 -1, i8* [[local2_cast]])
+; CHECK-NEXT: call i1 @foo.cold.1(i8* %local1_cast, i8* %local2_cast)
+; CHECK-NEXT: call void @llvm.lifetime.end.p0i8(i64 -1, i8* [[local1_cast]])
+; CHECK-NEXT: call void @llvm.lifetime.end.p0i8(i64 -1, i8* [[local2_cast]])
+; CHECK-NEXT: br i1
 
 outlinedPath:
   ; These two uses of stack slots are overlapping. This should prevent
diff --git a/llvm/test/Transforms/HotColdSplit/split-phis-in-exit-blocks.ll b/llvm/test/Transforms/HotColdSplit/split-phis-in-exit-blocks.ll
index 6b907ee..2f5360c 100644
--- a/llvm/test/Transforms/HotColdSplit/split-phis-in-exit-blocks.ll
+++ b/llvm/test/Transforms/HotColdSplit/split-phis-in-exit-blocks.ll
@@ -12,8 +12,11 @@
 ; CHECK-NEXT:  ]
 ;
 ; CHECK:  codeRepl:
+; CHECK-NEXT:    bitcast
+; CHECK-NEXT:    lifetime.start
 ; CHECK-NEXT:    call void @pluto.cold.1(i1* %tmp8.ce.loc)
 ; CHECK-NEXT:    %tmp8.ce.reload = load i1, i1* %tmp8.ce.loc
+; CHECK-NEXT:    lifetime.end
 ; CHECK-NEXT:    br label %bb7
 ;
 ; CHECK:  bb7: