[llvm] LoongArch: Improve detection of valid TripleABI (PR #147952)

[via llvm-commits]

https://github.com/mintsuki updated https://github.com/llvm/llvm-project/pull/147952

>From f8a753f1ed2e6ca13d5fbdd66021ec710505dae3 Mon Sep 17 00:00:00 2001
From: Mintsuki <mintsuki at protonmail.com>
Date: Thu, 10 Jul 2025 14:37:07 +0200
Subject: [PATCH] LoongArch: Improve detection of valid TripleABI

If the environment is considered to be the final triple component as a whole,
then the loongarch64 function computeTargetABI() should be changed not to rely
on hasEnvironment(), but, rather, to check if there is a non-unknown
environment set.

Without this change, using a (ideally valid) target of
loongarch64-unknown-none-elf, with a manually specified ABI of lp64s, will
result in a completely superfluous warning:

  warning: triple-implied ABI conflicts with provided target-abi 'lp64s', using target-abi
---
 llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchBaseInfo.cpp | 5 ++++-
 .../CodeGen/LoongArch/target-abi-from-triple-edge-cases.ll   | 4 ++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchBaseInfo.cpp b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchBaseInfo.cpp
index 03ce004ed33a5..532fe8f7c1912 100644
--- a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchBaseInfo.cpp
+++ b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchBaseInfo.cpp
@@ -52,6 +52,9 @@ static ABI getTripleABI(const Triple &TT) {
   bool Is64Bit = TT.isArch64Bit();
   ABI TripleABI;
   switch (TT.getEnvironment()) {
+  case llvm::Triple::EnvironmentType::UnknownEnvironment:
+    TripleABI = ABI_Unknown;
+    break;
   case llvm::Triple::EnvironmentType::GNUSF:
   case llvm::Triple::EnvironmentType::MuslSF:
     TripleABI = Is64Bit ? ABI_LP64S : ABI_ILP32S;
@@ -96,7 +99,7 @@ ABI computeTargetABI(const Triple &TT, const FeatureBitset &FeatureBits,
 
   // 1. If the '-target-abi' is valid, use it.
   if (IsABIValidForFeature(ArgProvidedABI)) {
-    if (TT.hasEnvironment() && ArgProvidedABI != TripleABI)
+    if (IsABIValidForFeature(TripleABI) && ArgProvidedABI != TripleABI)
       errs()
           << "warning: triple-implied ABI conflicts with provided target-abi '"
           << ABIName << "', using target-abi\n";
diff --git a/llvm/test/CodeGen/LoongArch/target-abi-from-triple-edge-cases.ll b/llvm/test/CodeGen/LoongArch/target-abi-from-triple-edge-cases.ll
index eb656ad94e28b..4fa2817bff32c 100644
--- a/llvm/test/CodeGen/LoongArch/target-abi-from-triple-edge-cases.ll
+++ b/llvm/test/CodeGen/LoongArch/target-abi-from-triple-edge-cases.ll
@@ -24,9 +24,9 @@
 ; NO-WARNING-NOT:  warning: triple-implied ABI conflicts with provided target-abi 'lp64d', using target-abi
 
 ;; Check that ILP32-on-LA64 and LP64-on-LA32 combinations are handled properly.
-; RUN: llc --mtriple=loongarch64 --target-abi=ilp32d --mattr=+d < %s 2>&1 \
+; RUN: llc --mtriple=loongarch64-linux-gnu --target-abi=ilp32d --mattr=+d < %s 2>&1 \
 ; RUN:   | FileCheck %s --check-prefixes=LP64D,32ON64
-; RUN: llc --mtriple=loongarch32 --target-abi=lp64d --mattr=+d < %s 2>&1 \
+; RUN: llc --mtriple=loongarch32-linux-gnu --target-abi=lp64d --mattr=+d < %s 2>&1 \
 ; RUN:   | FileCheck %s --check-prefixes=ILP32D,64ON32
 
 ; 32ON64: warning: 32-bit ABIs are not supported for 64-bit targets, ignoring and using triple-implied ABI