[llvm] [SPIR-V] Fix a crash in SPIRV Backend during the 'finalize lowering' stage on management of function forward calls (PR #97435)

[Vyacheslav Levytskyy via llvm-commits]

https://github.com/VyacheslavLevytskyy created https://github.com/llvm/llvm-project/pull/97435

This PR is to fix a crash in SPIRV Backend during the 'finalize lowering' stage on management of function forward calls. The reproducer is committed as a new test case.

>From 1ba391c5fe7437e9db75bb4fae9ce39277a2bb46 Mon Sep 17 00:00:00 2001
From: "Levytskyy, Vyacheslav" <vyacheslav.levytskyy at intel.com>
Date: Tue, 2 Jul 2024 09:33:43 -0700
Subject: [PATCH] fix crash during the 'finalize lowering' stage on management
 of function forward calls

---
 llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp |  4 +-
 .../function/forward-call-type-inference.ll   | 75 +++++++++++++++++++
 2 files changed, 77 insertions(+), 2 deletions(-)
 create mode 100644 llvm/test/CodeGen/SPIRV/function/forward-call-type-inference.ll

diff --git a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
index 5558c7a5a4a5f..e70ddc4d39455 100644
--- a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
@@ -318,15 +318,15 @@ Register SPIRVGlobalRegistry::buildConstantInt(uint64_t Val,
     if (EmitIR) {
       MIRBuilder.buildConstant(Res, *ConstInt);
     } else {
+      if (!SpvType)
+        SpvType = getOrCreateSPIRVIntegerType(BitWidth, MIRBuilder);
       MachineInstrBuilder MIB;
       if (Val) {
-        assert(SpvType);
         MIB = MIRBuilder.buildInstr(SPIRV::OpConstantI)
                   .addDef(Res)
                   .addUse(getSPIRVTypeID(SpvType));
         addNumImm(APInt(BitWidth, Val), MIB);
       } else {
-        assert(SpvType);
         MIB = MIRBuilder.buildInstr(SPIRV::OpConstantNull)
                   .addDef(Res)
                   .addUse(getSPIRVTypeID(SpvType));
diff --git a/llvm/test/CodeGen/SPIRV/function/forward-call-type-inference.ll b/llvm/test/CodeGen/SPIRV/function/forward-call-type-inference.ll
new file mode 100644
index 0000000000000..a1ef4f00dd4f5
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/function/forward-call-type-inference.ll
@@ -0,0 +1,75 @@
+; Adapted from Khronos Translator:
+; https://github.com/KhronosGroup/SPIRV-LLVM-Translator/blob/main/test/type-scavenger/equivalence.ll
+; The goal of the test is to ensure that the Backend doesn't crash during
+; the 'finalize lowering' stage on management of function forward calls.
+
+; RUN: llc -O0 -mtriple=spirv32-unknown-unknown %s -o - | FileCheck %s
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv32-unknown-unknown %s -o - -filetype=obj | spirv-val %}
+
+; RUN: llc -O0 -mtriple=spirv64-unknown-unknown %s -o - | FileCheck %s
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv64-unknown-unknown %s -o - -filetype=obj | spirv-val %}
+
+; CHECK-COUNT-9: OpFunction
+
+define spir_func void @_func1() {
+entry:
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.cond, %entry
+  %call3 = call spir_func ptr addrspace(4) @_func2()
+  %call5 = call spir_func ptr addrspace(4) @_func0(ptr addrspace(4) %call3, i64 0)
+  br label %for.cond
+}
+
+define spir_func void @_func3() {
+entry:
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.cond, %entry
+  %call3 = call spir_func ptr @_func4()
+  %call3.ascast = addrspacecast ptr %call3 to ptr addrspace(4)
+  %call5 = call spir_func ptr addrspace(4) @_func0(ptr addrspace(4) %call3.ascast, i64 0)
+  br label %for.cond
+}
+
+declare spir_func ptr addrspace(4) @_func5()
+
+define spir_func void @_func6(ptr addrspace(4) %call3.ascast) {
+entry:
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.cond, %entry
+  %call5 = call spir_func ptr addrspace(4) @_func0(ptr addrspace(4) %call3.ascast, i64 0)
+  br label %for.cond
+}
+
+define spir_func void @_func7() {
+entry:
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.cond, %entry
+  %call3 = call spir_func ptr addrspace(4) @_func5()
+  %call5 = call spir_func ptr addrspace(4) @_func0(ptr addrspace(4) %call3, i64 0)
+  br label %for.cond
+}
+
+declare spir_func ptr @_func4()
+
+declare spir_func ptr addrspace(4) @_func2()
+
+define spir_func ptr addrspace(4) @_func0(ptr addrspace(4) %this, i64 %index) {
+entry:
+  %arrayidx = getelementptr [5 x i32], ptr addrspace(4) %this, i64 0, i64 %index
+  ret ptr addrspace(4) null
+}
+
+define spir_func void @_func8() {
+entry:
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.cond, %entry
+  %call8 = call spir_func ptr addrspace(4) @_func0(ptr addrspace(4) null, i64 0)
+  br label %for.cond
+}
+
+uselistorder ptr @_func0, { 0, 4, 3, 2, 1 }