[llvm] 61480db - [Reduce] Argument reduction: shoe-horn new function into remaining uses of old function

[Roman Lebedev via llvm-commits]

Author: Roman Lebedev
Date: 2020-07-27T15:39:03+03:00
New Revision: 61480db6019d01a7a97de6ec64991664bf9b4996

URL: https://github.com/llvm/llvm-project/commit/61480db6019d01a7a97de6ec64991664bf9b4996
DIFF: https://github.com/llvm/llvm-project/commit/61480db6019d01a7a97de6ec64991664bf9b4996.diff

LOG: [Reduce] Argument reduction: shoe-horn new function into remaining uses of old function

Much like with function reduction, there may be remaining unhandled uses
of function, in particular in blockaddress. And in constants we can't
RAUW it with undef, because undef is not a function.
Instead, let's try to pretent that in the remaining cases, the new
signature didn't change, by bitcasting it.

A new (previously crashing) test case added.

Added: 
    llvm/test/Reduce/remove-function-arguments-of-funcs-used-in-blockaddress.ll

Modified: 
    llvm/test/Reduce/remove-invoked-functions.ll
    llvm/tools/llvm-reduce/deltas/ReduceArguments.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/test/Reduce/remove-function-arguments-of-funcs-used-in-blockaddress.ll b/llvm/test/Reduce/remove-function-arguments-of-funcs-used-in-blockaddress.ll
new file mode 100644
index 0000000000000..f1ad5db49bfb6
--- /dev/null
+++ b/llvm/test/Reduce/remove-function-arguments-of-funcs-used-in-blockaddress.ll
@@ -0,0 +1,30 @@
+; RUN: llvm-reduce --test FileCheck --test-arg --check-prefixes=CHECK-ALL,CHECK-INTERESTINGNESS --test-arg %s --test-arg --input-file %s -o %t
+; RUN: cat %t | FileCheck --check-prefixes=CHECK-ALL,CHECK-FINAL %s
+
+; CHECK-INTERESTINGNESS: define void @func(
+; CHECK-FINAL: define void @func()
+define void @func(i1 %arg) {
+; CHECK-ALL: bb:
+; CHECK-ALL: br label %bb4
+bb:
+  br label %bb4
+
+; CHECK-ALL: bb4
+bb4:
+; CHECK-INTERESTINGNESS; callbr void asm
+; CHECK-INTERESTINGNESS-SAME; blockaddress
+; CHECK-FINAL: callbr void asm sideeffect "", "X"(i8* blockaddress(@func, %bb11))
+; CHECK-ALL: to label %bb5 [label %bb11]
+  callbr void asm sideeffect "", "X"(i8* blockaddress(@func, %bb11))
+          to label %bb5 [label %bb11]
+
+; CHECK-ALL: bb5:
+; CHECK-ALL: br label %bb11
+bb5:
+  br label %bb11
+
+; CHECK-ALL: bb11:
+; CHECK-ALL: ret void
+bb11:
+  ret void
+}

diff  --git a/llvm/test/Reduce/remove-invoked-functions.ll b/llvm/test/Reduce/remove-invoked-functions.ll
index e4458e662fee3..d291859478033 100644
--- a/llvm/test/Reduce/remove-invoked-functions.ll
+++ b/llvm/test/Reduce/remove-invoked-functions.ll
@@ -23,7 +23,7 @@ define void @caller(i32 %arg) personality i8* bitcast (i32 (...)* @__gxx_persona
 ; CHECK-ALL: bb:
 bb:
 ; CHECK-INTERESTINGNESS: %i0 = invoke i32
-; CHECK-FINAL: %i0 = invoke i32 undef(i32 %arg)
+; CHECK-FINAL: %i0 = invoke i32 bitcast (i32 ()* @maybe_throwing_callee to i32 (i32)*)(i32 %arg)
 ; CHECK-ALL: to label %bb3 unwind label %bb1
   %i0 = invoke i32 @maybe_throwing_callee(i32 %arg)
           to label %bb3 unwind label %bb1

diff  --git a/llvm/tools/llvm-reduce/deltas/ReduceArguments.cpp b/llvm/tools/llvm-reduce/deltas/ReduceArguments.cpp
index 9488d71b71c35..c3c7dee83db10 100644
--- a/llvm/tools/llvm-reduce/deltas/ReduceArguments.cpp
+++ b/llvm/tools/llvm-reduce/deltas/ReduceArguments.cpp
@@ -94,7 +94,7 @@ static void extractArgumentsFromModule(std::vector<Chunk> ChunksToKeep,
     replaceFunctionCalls(*F, *ClonedFunc, ArgIndexesToKeep);
     // Rename Cloned Function to Old's name
     std::string FName = std::string(F->getName());
-    F->replaceAllUsesWith(UndefValue::get(F->getType()));
+    F->replaceAllUsesWith(ConstantExpr::getBitCast(ClonedFunc, F->getType()));
     F->eraseFromParent();
     ClonedFunc->setName(FName);
   }