[PATCH] D135738: [InstCombine] Bail out of casting calls when a conversion to byval is involved.

[Mike Hommey via Phabricator via llvm-commits]

glandium updated this revision to Diff 466997.
glandium added a comment.
Herald added subscribers: ormris, steven_wu.

Added testcase.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D135738/new/

https://reviews.llvm.org/D135738

Files:
  llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
  llvm/test/LTO/X86/cast-to-byval.ll


Index: llvm/test/LTO/X86/cast-to-byval.ll
===================================================================
--- /dev/null
+++ llvm/test/LTO/X86/cast-to-byval.ll
@@ -0,0 +1,33 @@
+; Check that cross-module function calls involving conversion to byval aren't
+; inlined.
+
+; RUN: split-file %s %t
+; RUN: llvm-as %t/t1.ll -o %t1
+; RUN: llvm-as %t/t2.ll -o %t2
+; RUN: llvm-lto %t1 %t2 -o %t0 -filetype=asm -save-merged-module -exported-symbol=testFoo
+; RUN: llvm-dis -o - %t0.merged.bc | FileCheck %s
+
+
+;--- t1.ll
+target datalayout = "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128"
+target triple = "i686-unknown-linux-gnu"
+
+define dso_local noundef i32 @testFoo(ptr nocapture noundef nonnull readonly align 4 dereferenceable(4) %0) local_unnamed_addr {
+  %2 = load i32, ptr %0, align 4
+  %3 = tail call i32 @getFooValue(i32 noundef %2)
+; CHECK: %3 = tail call i32 @getFooValue(i32 noundef %2)
+  ret i32 %3
+}
+
+declare i32 @getFooValue(i32 noundef) local_unnamed_addr
+
+;--- t2.ll
+target datalayout = "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128"
+target triple = "i686-unknown-linux-gnu"
+
+%0 = type { i32 }
+
+define i32 @getFooValue(ptr noalias nocapture noundef readonly byval(%0) dereferenceable(4) %0) unnamed_addr {
+  %2 = load i32, ptr %0, align 4
+  ret i32 %2
+}
Index: llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
===================================================================
--- llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -3395,6 +3395,10 @@
     if (CallerPAL.hasParamAttr(i, Attribute::SwiftError))
       return false;
 
+    if (!CallerPAL.hasParamAttr(i, Attribute::ByVal) &&
+        Callee->getAttributes().hasParamAttr(i, Attribute::ByVal))
+      return false; // Cannot transform to byval.
+
     // If the parameter is passed as a byval argument, then we have to have a
     // sized type and the sized type has to have the same size as the old type.
     if (ParamTy != ActTy && CallerPAL.hasParamAttr(i, Attribute::ByVal)) {


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