From 17c66f84bbf08ec6a1afd604ee5a1c3c55fe5ef4 Mon Sep 17 00:00:00 2001
From: Diana Picus <diana.picus@linaro.org>
Date: Fri, 21 Apr 2017 11:53:01 +0000
Subject: [PATCH] [ARM] GlobalISel: Make struct arguments fail elegantly

The condition in isSupportedType didn't handle struct/array arguments
properly. Fix the check and add a test to make sure we use the fallback
path in this kind of situation. The test deals with some common cases
where the call lowering should error out. There are still some issues
here that need to be addressed (tail calls come to mind), but they can
be addressed in other patches.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300967 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/ARMCallLowering.cpp            |  3 +-
 .../CodeGen/ARM/GlobalISel/arm-unsupported.ll | 80 +++++++++++++++++++
 2 files changed, 82 insertions(+), 1 deletion(-)
 create mode 100644 test/CodeGen/ARM/GlobalISel/arm-unsupported.ll

diff --git a/lib/Target/ARM/ARMCallLowering.cpp b/lib/Target/ARM/ARMCallLowering.cpp
index 94b317a8f98..13fb30767c9 100644
--- a/lib/Target/ARM/ARMCallLowering.cpp
+++ b/lib/Target/ARM/ARMCallLowering.cpp
@@ -35,7 +35,8 @@ ARMCallLowering::ARMCallLowering(const ARMTargetLowering &TLI)
 static bool isSupportedType(const DataLayout &DL, const ARMTargetLowering &TLI,
                             Type *T) {
   EVT VT = TLI.getValueType(DL, T, true);
-  if (!VT.isSimple() || VT.isVector())
+  if (!VT.isSimple() || VT.isVector() ||
+      !(VT.isInteger() || VT.isFloatingPoint()))
     return false;
 
   unsigned VTSize = VT.getSimpleVT().getSizeInBits();
diff --git a/test/CodeGen/ARM/GlobalISel/arm-unsupported.ll b/test/CodeGen/ARM/GlobalISel/arm-unsupported.ll
new file mode 100644
index 00000000000..e3680ed2b92
--- /dev/null
+++ b/test/CodeGen/ARM/GlobalISel/arm-unsupported.ll
@@ -0,0 +1,80 @@
+; RUN: llc -mtriple arm-unknown -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed='gisel*' %s -o - 2>&1 | FileCheck %s
+
+; This file checks that we use the fallback path for things that are known to
+; be unsupported on the ARM target. It should progressively shrink in size.
+
+define <4 x i32> @test_int_vectors(<4 x i32> %a, <4 x i32> %b) {
+; CHECK: remark: {{.*}} unable to lower arguments: <4 x i32> (<4 x i32>, <4 x i32>)*
+; CHECK-LABEL: warning: Instruction selection used fallback path for test_int_vectors
+  %res = add <4 x i32> %a, %b
+  ret <4 x i32> %res
+}
+
+define <4 x float> @test_float_vectors(<4 x float> %a, <4 x float> %b) {
+; CHECK: remark: {{.*}} unable to lower arguments: <4 x float> (<4 x float>, <4 x float>)*
+; CHECK-LABEL: warning: Instruction selection used fallback path for test_float_vectors
+  %res = fadd <4 x float> %a, %b
+  ret <4 x float> %res
+}
+
+define i64 @test_i64(i64 %a, i64 %b) {
+; CHECK: remark: {{.*}} unable to lower arguments: i64 (i64, i64)*
+; CHECK-LABEL: warning: Instruction selection used fallback path for test_i64
+  %res = add i64 %a, %b
+  ret i64 %res
+}
+
+define i128 @test_i128(i128 %a, i128 %b) {
+; CHECK: remark: {{.*}} unable to lower arguments: i128 (i128, i128)*
+; CHECK-LABEL: warning: Instruction selection used fallback path for test_i128
+  %res = add i128 %a, %b
+  ret i128 %res
+}
+
+define i17 @test_funny_ints(i17 %a, i17 %b) {
+; CHECK: remark: {{.*}} unable to lower arguments: i17 (i17, i17)*
+; CHECK-LABEL: warning: Instruction selection used fallback path for test_funny_ints
+  %res = add i17 %a, %b
+  ret i17 %res
+}
+
+define half @test_half(half %a, half %b) {
+; CHECK: remark: {{.*}} unable to lower arguments: half (half, half)*
+; CHECK-LABEL: warning: Instruction selection used fallback path for test_half
+  %res = fadd half %a, %b
+  ret half %res
+}
+
+; On ARM, clang lowers structs to arrays.
+define void @test_arrays([2 x i32] %this.could.come.from.a.struct) {
+; CHECK: remark: {{.*}} unable to lower arguments: void ([2 x i32])*
+; CHECK-LABEL: warning: Instruction selection used fallback path for test_arrays
+  ret void
+}
+
+define void @test_structs({i32, i32} %struct) {
+; CHECK: remark: {{.*}} unable to lower arguments: void ({ i32, i32 })*
+; CHECK-LABEL: warning: Instruction selection used fallback path for test_structs
+  ret void
+}
+
+define void @test_vararg_definition(i32 %a, ...) {
+; CHECK: remark: {{.*}} unable to lower arguments: void (i32, ...)*
+; CHECK-LABEL: warning: Instruction selection used fallback path for test_vararg_definition
+  ret void
+}
+
+define void @test_vararg_call(i32 %a) {
+; CHECK: remark: {{.*}} unable to translate instruction: call
+; CHECK-LABEL: warning: Instruction selection used fallback path for test_vararg_call
+  call void(i32, ...) @test_vararg_definition(i32 %a, i32 %a, i32 %a)
+  ret void
+}
+
+define i32 @test_thumb(i32 %a) #0 {
+; CHECK: remark: {{.*}} unable to lower arguments: i32 (i32)*
+; CHECK-LABEL: warning: Instruction selection used fallback path for test_thumb
+  ret i32 %a
+}
+
+attributes #0 = { "target-features"="+thumb-mode" }