Dereferenceable, dereferenceable_or_null metadata for loads

Summary:
Introduce dereferenceable, dereferenceable_or_null metadata for loads
with the same semantic as corresponding attributes.

This patch depends on http://reviews.llvm.org/D9253

Patch by Artur Pilipenko!

Reviewers: hfinkel, sanjoy, reames

Reviewed By: sanjoy, reames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9365

llvm-svn: 237720

1 files changed, 32 insertions, 1 deletions

diff --git a/llvm/test/Analysis/ValueTracking/memory-dereferenceable.ll b/llvm/test/Analysis/ValueTracking/memory-dereferenceable.ll
index 7f178756a8b..c3aba3a7dc0 100644
--- a/llvm/test/Analysis/ValueTracking/memory-dereferenceable.ll
+++ b/llvm/test/Analysis/ValueTracking/memory-dereferenceable.ll
@@ -8,6 +8,7 @@ target datalayout = "e"
 declare zeroext i1 @return_i1()
 
 @globalstr = global [6 x i8] c"hello\00"
+@globali32ptr = external global i32*
 
 define void @test(i32 addrspace(1)* dereferenceable(8) %dparam) gc "statepoint-example" {
 ; CHECK: The following are dereferenceable:
@@ -15,7 +16,12 @@ define void @test(i32 addrspace(1)* dereferenceable(8) %dparam) gc "statepoint-e
 ; CHECK: %alloca
 ; CHECK: %dparam
 ; CHECK: %relocate
+; CHECK: %d4_load
+; CHECK: %d_or_null_non_null_load
 ; CHECK-NOT: %nparam
+; CHECK-NOT: %nd_load
+; CHECK-NOT: %d2_load
+; CHECK-NOT: %d_or_null_load
 entry:
     %globalptr = getelementptr inbounds [6 x i8], [6 x i8]* @globalstr, i32 0, i32 0
     %load1 = load i8, i8* %globalptr
@@ -27,8 +33,33 @@ entry:
     %load4 = load i32, i32 addrspace(1)* %relocate
     %nparam = getelementptr i32, i32 addrspace(1)* %dparam, i32 5
     %load5 = load i32, i32 addrspace(1)* %nparam
+
+    ; Load from a non-dereferenceable load
+    %nd_load = load i32*, i32** @globali32ptr, !dereferenceable !0
+    %load6 = load i32, i32* %nd_load
+
+    ; Load from a dereferenceable load
+    %d4_load = load i32*, i32** @globali32ptr, !dereferenceable !0
+    %load7 = load i32, i32* %d4_load
+
+    ; Load from an offset not covered by the dereferenceable portion
+    %d2_load = load i32*, i32** @globali32ptr, !dereferenceable !1
+    %load8 = load i32, i32* %d2_load
+
+    ; Load from a potentially null pointer with dereferenceable_or_null
+    %d_or_null_load = load i32*, i32** @globali32ptr, !dereferenceable_or_null !0
+    %load9 = load i32, i32* %d_or_null_load
+
+    ; Load from a non-null pointer with dereferenceable_or_null
+    %d_or_null_non_null_load = load i32*, i32** @globali32ptr, !nonnull !2, !dereferenceable_or_null !0
+    %load10 = load i32, i32* %d_or_null_non_null_load
+
     ret void
 }
 
 declare i32 @llvm.experimental.gc.statepoint.p0f_i1f(i64, i32, i1 ()*, i32, i32, ...)
-declare i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32, i32, i32)
\ No newline at end of file
+declare i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32, i32, i32)
+
+!0 = !{i64 4}
+!1 = !{i64 2}
+!2 = !{}