[llvm] [InferAddressSpaces] Extend undef pointer operand support to phi inst (PR #159548)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,36 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -S -passes=infer-address-spaces %s | FileCheck %s
+
+define void @phi_undef(ptr addrspace(1) %arg, <2 x ptr addrspace(1)> %arg1) {
+; CHECK-LABEL: @phi_undef(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = call i1 @is_leader()
+; CHECK-NEXT:    br i1 [[TMP0]], label [[LEADER:%.*]], label [[MERGE:%.*]]
+; CHECK:       leader:
+; CHECK-NEXT:    br label [[MERGE]]
+; CHECK:       merge:
+; CHECK-NEXT:    [[I:%.*]] = phi ptr addrspace(1) [ [[ARG:%.*]], [[LEADER]] ], [ undef, [[ENTRY:%.*]] ]
+; CHECK-NEXT:    [[I2:%.*]] = phi <2 x ptr addrspace(1)> [ [[ARG1:%.*]], [[LEADER]] ], [ undef, [[ENTRY]] ]
+; CHECK-NEXT:    [[TMP1:%.*]] = addrspacecast <2 x ptr addrspace(1)> [[I2]] to <2 x ptr>
+; CHECK-NEXT:    [[J:%.*]] = load i8, ptr addrspace(1) [[I]], align 1
+; CHECK-NEXT:    [[J1:%.*]] = icmp eq <2 x ptr> [[TMP1]], zeroinitializer
+; CHECK-NEXT:    ret void
+;
+entry:
+  %0 = call i1 @is_leader()
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arsenm wrote:

Use named values 

https://github.com/llvm/llvm-project/pull/159548