From 8e5b96cce91e63908a91cdaef81e9a1c993b18f2 Mon Sep 17 00:00:00 2001
From: Jeffrey Byrnes <Jeffrey.Byrnes@amd.com>
Date: Thu, 6 Oct 2022 14:29:04 -0700
Subject: [PATCH] [AMDGPU] Add test coverage to ensure first regallocfast only
 allocates SGPR

Register allocation is split into two passes, and the expected behavior is that the first pass only should only work on virtual SGPRs. Whereas the second pass works on virtual VGPRs. This adds a test case which breaks if the first pass allocates VGPRs.

Differential Revision: https://reviews.llvm.org/D135331
---
 .../test/CodeGen/AMDGPU/fastregalloc-sgpr-only.mir | 32 ++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 llvm/test/CodeGen/AMDGPU/fastregalloc-sgpr-only.mir

diff --git a/llvm/test/CodeGen/AMDGPU/fastregalloc-sgpr-only.mir b/llvm/test/CodeGen/AMDGPU/fastregalloc-sgpr-only.mir
new file mode 100644
index 0000000..c57919d
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/fastregalloc-sgpr-only.mir
@@ -0,0 +1,32 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -O0 -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -start-before=regallocfast,0 --stop-after=regallocfast,0 -o - %s | FileCheck -check-prefix=GCN %s
+
+---
+name: copy_vgpr_allocation
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0, $vgpr1, $vgpr4, $vgpr5
+    ; GCN-LABEL: name: copy_vgpr_allocation
+    ; GCN: liveins: $vgpr0, $vgpr1, $vgpr4, $vgpr5
+    ; GCN-NEXT: {{  $}}
+    ; GCN-NEXT: [[COPY:%[0-9]+]]:vreg_64 = COPY killed $vgpr0_vgpr1
+    ; GCN-NEXT: FLAT_STORE_DWORDX2 killed $vgpr4_vgpr5, [[COPY]], 0, 0, implicit $exec, implicit $flat_scr
+    %14:vreg_64 = COPY $vgpr0_vgpr1
+    FLAT_STORE_DWORDX2 $vgpr4_vgpr5, %14:vreg_64, 0, 0, implicit $exec, implicit $flat_scr
+...
+
+
+---
+name: copy_sgpr_allocation
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $sgpr0, $sgpr1, $sgpr4
+    ; GCN-LABEL: name: copy_sgpr_allocation
+    ; GCN: liveins: $sgpr0, $sgpr1, $sgpr4
+    ; GCN-NEXT: {{  $}}
+    ; GCN-NEXT: S_STORE_DWORD_SGPR killed $sgpr4, killed renamable $sgpr0_sgpr1, undef $m0, 0
+    %14:sreg_64 = COPY $sgpr0_sgpr1
+    S_STORE_DWORD_SGPR $sgpr4, %14:sreg_64, undef $m0, 0
+...
-- 
2.7.4