[WebAssembly] Insert COPY_LOCAL between CopyToReg and FrameIndex DAG nodes
CopyToReg nodes don't support FrameIndex operands. Other targets select
the FI to some LEA-like instruction, but since we don't have that, we
need to insert some kind of instruction that can take an FI operand and
produces a value usable by CopyToReg (i.e. in a vreg). So insert a dummy
copy_local between Op and its FI operand. This results in a redundant
copy which we should optimize away later (maybe in the post-FI-lowering
peephole pass).
Differential Revision: http://reviews.llvm.org/D17213
llvm-svn: 260987
diff --git a/llvm/test/CodeGen/WebAssembly/userstack.ll b/llvm/test/CodeGen/WebAssembly/userstack.ll
index 435e1dd..b5e711f 100644
--- a/llvm/test/CodeGen/WebAssembly/userstack.ll
+++ b/llvm/test/CodeGen/WebAssembly/userstack.ll
@@ -160,4 +160,25 @@
ret void
}
+; The use of the alloca in a phi causes a CopyToReg DAG node to be generated,
+; which has to have special handling because CopyToReg can't have a FI operand
+; CHECK-LABEL: copytoreg_fi:
+define void @copytoreg_fi(i1 %cond, i32* %b) {
+entry:
+ ; CHECK: i32.const [[L2:.+]]=, 16
+ ; CHECK-NEXT: i32.sub [[SP:.+]]=, {{.+}}, [[L2]]
+ %addr = alloca i32
+ ; CHECK: i32.const [[OFF:.+]]=, 12
+ ; CHECK-NEXT: i32.add [[ADDR:.+]]=, [[SP]], [[OFF]]
+ ; CHECK-NEXT: copy_local [[COPY:.+]]=, [[ADDR]]
+ br label %body
+body:
+ %a = phi i32* [%addr, %entry], [%b, %body]
+ store i32 1, i32* %a
+ ; CHECK: i32.store {{.*}}, 0([[COPY]]),
+ br i1 %cond, label %body, label %exit
+exit:
+ ret void
+}
+
; TODO: test over-aligned alloca