[mips] Show an error if 64-bit target triple provided with 32-bit CPU

When a 64-bit triple is used emit an error if the CPU only supports
32-bit code.

Patch by Miloš Stojanović.

Differential Revision: https://reviews.llvm.org/D70018

2 files changed, 20 insertions, 0 deletions

diff --git a/llvm/lib/Target/Mips/MipsSubtarget.cpp b/llvm/lib/Target/Mips/MipsSubtarget.cpp
index 29e557c6052..133b818114c 100644
--- a/llvm/lib/Target/Mips/MipsSubtarget.cpp
+++ b/llvm/lib/Target/Mips/MipsSubtarget.cpp
@@ -256,6 +256,10 @@ MipsSubtarget::initializeSubtargetDependencies(StringRef CPU, StringRef FS,
     stackAlignment = Align(8);
   }
 
+  if ((isABI_N32() || isABI_N64()) && !isGP64bit())
+    report_fatal_error("64-bit code requested on a subtarget that doesn't "
+                       "support it!");
+
   return *this;
 }
 
diff --git a/llvm/test/CodeGen/Mips/cpus-no-mips64.ll b/llvm/test/CodeGen/Mips/cpus-no-mips64.ll
new file mode 100644
index 00000000000..301f6c2152e
--- /dev/null
+++ b/llvm/test/CodeGen/Mips/cpus-no-mips64.ll
@@ -0,0 +1,16 @@
+; Check that we reject 64-bit mode on 32-bit only CPUs.
+
+; RUN: not llc < %s -o /dev/null -mtriple=mips64 -mcpu=mips1 2>&1 | FileCheck %s
+; RUN: not llc < %s -o /dev/null -mtriple=mips64 -mcpu=mips2 2>&1 | FileCheck %s
+
+; RUN: not llc < %s -o /dev/null -mtriple=mips64 -mcpu=mips32 2>&1 | FileCheck %s
+; RUN: not llc < %s -o /dev/null -mtriple=mips64 -mcpu=mips32r2 2>&1 | FileCheck %s
+; RUN: not llc < %s -o /dev/null -mtriple=mips64 -mcpu=mips32r3 2>&1 | FileCheck %s
+; RUN: not llc < %s -o /dev/null -mtriple=mips64 -mcpu=mips32r5 2>&1 | FileCheck %s
+; RUN: not llc < %s -o /dev/null -mtriple=mips64 -mcpu=mips32r6 2>&1 | FileCheck %s
+
+; CHECK: LLVM ERROR: 64-bit code requested on a subtarget that doesn't support it!
+
+define void @foo() {
+  ret void
+}