[llvm] [GlobalISel] Bail out early for big-endian (PR #103310)

[David Green via llvm-commits]

https://github.com/davemgreen created https://github.com/llvm/llvm-project/pull/103310

If we continue through the function we can currently hit crashes. We can bail out early and fall back to SDAG.

Fixes #103032

>From d541ac20dce45d054d4e1c98963b880579d2302c Mon Sep 17 00:00:00 2001
From: David Green <david.green at arm.com>
Date: Tue, 13 Aug 2024 17:48:00 +0100
Subject: [PATCH] [GlobalISel] Bail out early for big-endian

If we continue through the function we can currently hit crashes. We can bail
out early and fall back to SDAG.
---
 llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp   |  1 +
 .../AArch64/GlobalISel/endian_fallback.ll      | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+)
 create mode 100644 llvm/test/CodeGen/AArch64/GlobalISel/endian_fallback.ll

diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index 219c60eab04f5a..4f5a26e72e539b 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -3889,6 +3889,7 @@ bool IRTranslator::runOnMachineFunction(MachineFunction &CurMF) {
                                F.getSubprogram(), &F.getEntryBlock());
     R << "unable to translate in big endian mode";
     reportTranslationError(*MF, *TPC, *ORE, R);
+    return false;
   }
 
   // Release the per-function state when we return, whether we succeeded or not.
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/endian_fallback.ll b/llvm/test/CodeGen/AArch64/GlobalISel/endian_fallback.ll
new file mode 100644
index 00000000000000..e995d60c05d13a
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/endian_fallback.ll
@@ -0,0 +1,18 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc -mtriple aarch64-unknown-linux-musl -O0 < %s | FileCheck %s --check-prefix=CHECK-LE
+; RUN: llc -mtriple aarch64_be-unknown-linux-musl -O0 < %s | FileCheck %s --check-prefix=CHECK-BE
+
+; Make sure we fall-back to SDAG for BE targets.
+
+define <4 x i6> @foo(float %0, <4 x i6> %1) {
+; CHECK-LE-LABEL: foo:
+; CHECK-LE:       // %bb.0:
+; CHECK-LE-NEXT:    fmov d0, d1
+; CHECK-LE-NEXT:    ret
+;
+; CHECK-BE-LABEL: foo:
+; CHECK-BE:       // %bb.0:
+; CHECK-BE-NEXT:    fmov d0, d1
+; CHECK-BE-NEXT:    ret
+  ret <4 x i6> %1
+}