Rebased PNaCl localmods in LLVM to 223109

test/Transforms/NaCl/expand-tls-phi.ll

+; RUN: opt < %s -nacl-expand-tls -S | FileCheck %s
+
+
+@tvar = thread_local global i32 123
+
+define i32* @get_tvar(i1 %cmp) {
+entry:
+  br i1 %cmp, label %return, label %else
+
+else:
+  br label %return
+
+return:
+  %result = phi i32* [ @tvar, %entry ], [ null, %else ]
+  ret i32* %result
+}
+; The TLS access gets pushed back into the PHI node's incoming block,
+; which might be suboptimal but works in all cases.
+; CHECK: define i32* @get_tvar(i1 %cmp) {
+; CHECK: entry:
+; CHECK: %field = getelementptr %tls_struct* %tls_struct, i32 -1, i32 0, i32 0
+; CHECK: else:
+; CHECK: return:
+; CHECK: %result = phi i32* [ %field, %entry ], [ null, %else ]
+
+
+; This tests that ExpandTls correctly handles a PHI node that contains
+; the same TLS variable twice.  Using replaceAllUsesWith() is not
+; correct on a PHI node when the new instruction has to be added to an
+; incoming block.
+define i32* @tls_phi_twice(i1 %arg) {
+  br i1 %arg, label %iftrue, label %iffalse
+iftrue:
+  br label %exit
+iffalse:
+  br label %exit
+exit:
+  %result = phi i32* [ @tvar, %iftrue ], [ @tvar, %iffalse ]
+  ret i32* %result
+}
+; CHECK: define i32* @tls_phi_twice(i1 %arg) {
+; CHECK: iftrue:
+; CHECK: %field{{.*}} = getelementptr %tls_struct* %tls_struct{{.*}}, i32 -1, i32 0, i32 0
+; CHECK: iffalse:
+; CHECK: %field{{.*}} = getelementptr %tls_struct* %tls_struct{{.*}}, i32 -1, i32 0, i32 0
+; CHECK: exit:
+; CHECK: %result = phi i32* [ %field{{.*}}, %iftrue ], [ %field{{.*}}, %iffalse ]
+
+
+; In this corner case, ExpandTls must expand out @tvar only once,
+; otherwise it will produce invalid IR.
+define i32* @tls_phi_multiple_entry(i1 %arg) {
+entry:
+  br i1 %arg, label %done, label %done
+done:
+  %result = phi i32* [ @tvar, %entry ], [ @tvar, %entry ]
+  ret i32* %result
+}
+; CHECK: define i32* @tls_phi_multiple_entry(i1 %arg) {
+; CHECK: %result = phi i32* [ %field, %entry ], [ %field, %entry ]