[llvm] [LoongArch] Assume no-op addrspacecasts by default (PR #82332)

[via llvm-commits]

https://github.com/heiher updated https://github.com/llvm/llvm-project/pull/82332

>From 525b1a631e3d858df1cf5e9e64dace666dc851bb Mon Sep 17 00:00:00 2001
From: WANG Rui <wangrui at loongson.cn>
Date: Tue, 20 Feb 2024 17:41:36 +0800
Subject: [PATCH 1/2] [LoongArch] Assume no-op addrspacecasts by default

Fixes #82330
---
 .../Target/LoongArch/LoongArchTargetMachine.h |  5 ++
 llvm/test/CodeGen/LoongArch/addrspacecast.ll  | 47 +++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100644 llvm/test/CodeGen/LoongArch/addrspacecast.ll

diff --git a/llvm/lib/Target/LoongArch/LoongArchTargetMachine.h b/llvm/lib/Target/LoongArch/LoongArchTargetMachine.h
index 7d39d47e86b363..fa9bc7608e7d2c 100644
--- a/llvm/lib/Target/LoongArch/LoongArchTargetMachine.h
+++ b/llvm/lib/Target/LoongArch/LoongArchTargetMachine.h
@@ -45,6 +45,11 @@ class LoongArchTargetMachine : public LLVMTargetMachine {
   MachineFunctionInfo *
   createMachineFunctionInfo(BumpPtrAllocator &Allocator, const Function &F,
                             const TargetSubtargetInfo *STI) const override;
+
+  // Addrspacecasts are always noops.
+  bool isNoopAddrSpaceCast(unsigned SrcAS, unsigned DestAS) const override {
+    return true;
+  }
 };
 
 } // end namespace llvm
diff --git a/llvm/test/CodeGen/LoongArch/addrspacecast.ll b/llvm/test/CodeGen/LoongArch/addrspacecast.ll
new file mode 100644
index 00000000000000..2b90f32d029795
--- /dev/null
+++ b/llvm/test/CodeGen/LoongArch/addrspacecast.ll
@@ -0,0 +1,47 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=loongarch32 -verify-machineinstrs < %s | FileCheck %s --check-prefix=LA32
+; RUN: llc -mtriple=loongarch64 -verify-machineinstrs < %s | FileCheck %s --check-prefix=LA64
+
+define void @cast0(ptr addrspace(1) %ptr) {
+; LA32-LABEL: cast0:
+; LA32:       # %bb.0:
+; LA32-NEXT:    st.w $zero, $a0, 0
+; LA32-NEXT:    ret
+;
+; LA64-LABEL: cast0:
+; LA64:       # %bb.0:
+; LA64-NEXT:    st.w $zero, $a0, 0
+; LA64-NEXT:    ret
+  %ptr0 = addrspacecast ptr addrspace(1) %ptr to ptr addrspace(0)
+  store i32 0, ptr %ptr0
+  ret void
+}
+
+define void @cast1(ptr %ptr) {
+; LA32-LABEL: cast1:
+; LA32:       # %bb.0:
+; LA32-NEXT:    addi.w $sp, $sp, -16
+; LA32-NEXT:    .cfi_def_cfa_offset 16
+; LA32-NEXT:    st.w $ra, $sp, 12 # 4-byte Folded Spill
+; LA32-NEXT:    .cfi_offset 1, -4
+; LA32-NEXT:    bl %plt(foo)
+; LA32-NEXT:    ld.w $ra, $sp, 12 # 4-byte Folded Reload
+; LA32-NEXT:    addi.w $sp, $sp, 16
+; LA32-NEXT:    ret
+;
+; LA64-LABEL: cast1:
+; LA64:       # %bb.0:
+; LA64-NEXT:    addi.d $sp, $sp, -16
+; LA64-NEXT:    .cfi_def_cfa_offset 16
+; LA64-NEXT:    st.d $ra, $sp, 8 # 8-byte Folded Spill
+; LA64-NEXT:    .cfi_offset 1, -8
+; LA64-NEXT:    bl %plt(foo)
+; LA64-NEXT:    ld.d $ra, $sp, 8 # 8-byte Folded Reload
+; LA64-NEXT:    addi.d $sp, $sp, 16
+; LA64-NEXT:    ret
+  %castptr = addrspacecast ptr %ptr to ptr addrspace(10)
+  call void @foo(ptr addrspace(10) %castptr)
+  ret void
+}
+
+declare void @foo(ptr addrspace(10))

>From 46c7cbe7d1e466774a907b21756763ccaaf1aa7a Mon Sep 17 00:00:00 2001
From: WANG Rui <wangrui at loongson.cn>
Date: Wed, 21 Feb 2024 20:48:18 +0800
Subject: [PATCH 2/2] Use canonicalized options

---
 llvm/test/CodeGen/LoongArch/addrspacecast.ll | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/llvm/test/CodeGen/LoongArch/addrspacecast.ll b/llvm/test/CodeGen/LoongArch/addrspacecast.ll
index 2b90f32d029795..7875562331be09 100644
--- a/llvm/test/CodeGen/LoongArch/addrspacecast.ll
+++ b/llvm/test/CodeGen/LoongArch/addrspacecast.ll
@@ -1,6 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -mtriple=loongarch32 -verify-machineinstrs < %s | FileCheck %s --check-prefix=LA32
-; RUN: llc -mtriple=loongarch64 -verify-machineinstrs < %s | FileCheck %s --check-prefix=LA64
+; RUN: llc --mtriple=loongarch32 --verify-machineinstrs < %s | FileCheck %s --check-prefix=LA32
+; RUN: llc --mtriple=loongarch64 --verify-machineinstrs < %s | FileCheck %s --check-prefix=LA64
 
 define void @cast0(ptr addrspace(1) %ptr) {
 ; LA32-LABEL: cast0: