[llvm-reduce] Do not convert lifetime operand to argument

The lifetime argument is now required to be an alloca, so do not
try to convert it to a function argument.

The reduction is now going to leave behind an unused alloca with
lifetime markers, which should be cleaned up separately.

Author: nikic

llvm/test/tools/llvm-reduce/operands-to-args-lifetimes.ll

@@ -0,0 +1,18 @@
+; RUN: llvm-reduce %s -o %t --abort-on-invalid-reduction --delta-passes=operands-to-args --test FileCheck --test-arg %s --test-arg --check-prefix=INTERESTING --test-arg --input-file
+; RUN: FileCheck %s --input-file %t --check-prefix=REDUCED
+
+; INTERESTING: store
+; REDUCED: define void @test(ptr %a) {
+; REDUCED-NEXT: %a1 = alloca i32
+; REDUCED-NEXT: call void @llvm.lifetime.start.p0(i64 4, ptr %a1)
+; REDUCED-NEXT: store i32 0, ptr %a
+; REDUCED-NEXT: store i32 1, ptr %a
+; REDUCED-NEXT: call void @llvm.lifetime.end.p0(i64 4, ptr %a1)
+define void @test() {
+  %a = alloca i32
+  call void @llvm.lifetime.start.p0(i64 4, ptr %a)
+  store i32 0, ptr %a
+  store i32 1, ptr %a
+  call void @llvm.lifetime.end.p0(i64 4, ptr %a)
+  ret void
+}

llvm/tools/llvm-reduce/deltas/ReduceOperandsToArgs.cpp

@@ -13,6 +13,7 @@
 #include "llvm/IR/InstIterator.h"
 #include "llvm/IR/InstrTypes.h"
 #include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Operator.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Cloning.h"
@@ -49,6 +50,10 @@ static bool canReduceUse(Use &Op) {
     if (&CI->getCalledOperandUse() == &Op)
       return false;
 
+  // lifetime.start/lifetime.end require alloca argument.
+  if (isa<LifetimeIntrinsic>(Op.getUser()))
+    return false;
+
   return true;
 }