[PATCH] D42846: [PartialInlining] Use isInlineViable to detect constructs preventing inlining.

[Florian Hahn via Phabricator via llvm-commits]

fhahn created this revision.
fhahn added reviewers: efriedma, sfertile, davide, davidxl.
Herald added a subscriber: eraman.

Currently, the partial inliner calls InlineFunction, without checking
if the function contains constructs preventing inlining. In some cases,
e.g. Varargs, CodeExtractor will fail extracting constructs preventing
inlining, but in others it currently does not. This patch uses
isInlineViable before calling InlineFunction. An alternative
approach would be to update CodeExtractor to only extract inlinable
blocks and turn the if into an assertion. But that would make
CodeExtractor less general.


https://reviews.llvm.org/D42846

Files:
  lib/Transforms/IPO/PartialInlining.cpp
  test/Transforms/CodeExtractor/PartialInlineNotViable.ll


Index: test/Transforms/CodeExtractor/PartialInlineNotViable.ll
===================================================================
--- /dev/null
+++ test/Transforms/CodeExtractor/PartialInlineNotViable.ll
@@ -0,0 +1,62 @@
+; RUN: opt < %s -partial-inliner -skip-partial-inlining-cost-analysis -S | FileCheck %s
+;
+
+define i32 @callee_indr_branch(i32 %v) {
+entry:
+  %cmp = icmp sgt i32 %v, 2000
+  %addr = select i1 %cmp, i8* blockaddress(@callee_indr_branch, %if.then), i8* blockaddress(@callee_indr_branch, %if.end)
+  indirectbr i8* %addr, [ label %if.then, label %if.end]
+
+if.then:                                          ; preds = %entry
+  %mul = mul nsw i32 %v, 10
+  br label %if.then2
+
+if.then2:
+  %sub = sub i32 %v, 10
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  %v2 = phi i32 [ %v, %entry ], [ %mul, %if.then2 ]
+  %add = add nsw i32 %v2, 200
+  ret i32 %add
+}
+
+declare void @use_fp(i8 *)
+declare void @llvm.localescape(...)
+declare i8* @llvm.frameaddress(i32)
+declare i8* @llvm.localrecover(i8*, i8*, i32)
+
+
+
+define i32 @callee_frameescape(i32 %v) {
+entry:
+  %a = alloca i32
+  call void (...) @llvm.localescape(i32* %a)
+  %cmp = icmp sgt i32 %v, 2000
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  %mul = mul nsw i32 %v, 10
+  br label %if.then2
+
+if.then2:
+  %sub = sub i32 %v, 10
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  %v2 = phi i32 [ %v, %entry ], [ %mul, %if.then2 ]
+  %add = add nsw i32 %v2, 200
+  ret i32 %add
+}
+
+
+; CHECK-LABEL: @caller
+; CHECK: %r1 = call i32 @callee_indr_branch(i32 %v)
+; CHECK-NEXT: %r2 = call i32 @callee_frameescape(i32 %v)
+define i32 @caller(i32 %v) {
+entry:
+  %r1 = call i32 @callee_indr_branch(i32 %v)
+  %r2 = call i32 @callee_frameescape(i32 %v)
+  %res = add i32 %r1, %r2
+  ret i32 %res
+}
Index: lib/Transforms/IPO/PartialInlining.cpp
===================================================================
--- lib/Transforms/IPO/PartialInlining.cpp
+++ lib/Transforms/IPO/PartialInlining.cpp
@@ -1373,6 +1373,9 @@
     return false;
   }
 
+  if (!isInlineViable(*Cloner.ClonedFunc))
+    return false;
+
   assert(Cloner.OrigFunc->user_begin() == Cloner.OrigFunc->user_end() &&
          "F's users should all be replaced!");
 


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