[PATCH] D45343: Always remove null check before free

[Dávid Bolvanský via Phabricator via llvm-commits]

xbolva00 updated this revision to Diff 141324.
xbolva00 added a comment.

Added test


https://reviews.llvm.org/D45343

Files:
  lib/Transforms/InstCombine/InstructionCombining.cpp
  mypatch.patch
  test/Transforms/InstCombine/null-check-free.ll


Index: test/Transforms/InstCombine/null-check-free.ll
===================================================================
--- /dev/null
+++ test/Transforms/InstCombine/null-check-free.ll
@@ -0,0 +1,20 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+declare i8* @malloc(i32) #1
+
+declare i32 @free(...) #1
+
+; CHECK-LABEL: define i8* @nullcheckfree()(
+; CHECK:       entry:
+; CHECK-NEXT:    %p = alloca i8*, align 4
+; CHECK-NEXT:    %call = call i8* @malloc(i32 10)
+; CHECK-NEXT:    %tobool = icmp ne i8* %call, null
+; CHECK-NEXT:    br i1 %tobool, label %if.then, label %if.end
+; CHECK:       if.end: 
+; CHECK-NEXT:    %0 = load i8*, i8** %p, align 4
+; CHECK-NEXT:    %call1 = call i32 bitcast (i32 (...)* @free to i32 (i8*)*)(i8* %0)
+; CHECK-NEXT:    br label %if.end
+; CHECK:       if.end:
+; CHECK-NEXT:    %1 = load i8*, i8** %p, align 4
+; CHECK-NEXT:    ret i8* %1
+}
\ No newline at end of file
Index: lib/Transforms/InstCombine/InstructionCombining.cpp
===================================================================
--- lib/Transforms/InstCombine/InstructionCombining.cpp
+++ lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -2333,9 +2333,8 @@
   // if (foo) free(foo);
   // into
   // free(foo);
-  if (MinimizeSize)
-    if (Instruction *I = tryToMoveFreeBeforeNullTest(FI))
-      return I;
+  if (Instruction *I = tryToMoveFreeBeforeNullTest(FI))
+    return I;
 
   return nullptr;
 }


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D45343.141324.patch
Type: text/x-patch
Size: 1428 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20180406/315ccdcf/attachment.bin>