unittests/ASM: Adds test for too large branch objects

unittests/ASM/FEX_bugs/BitConditionCheck.asm

@@ -0,0 +1,39 @@
+%ifdef CONFIG
+{
+  "RegData": {
+    "RAX": "1"
+  },
+  "Env": { "FEX_MAXINST" : "41010", "FEX_MULTIBLOCK": "1", "FEX_TSOENABLED": "0" }
+}
+%endif
+
+; FEX-Emu had a bug where it tried to encode too large of a tbz/tbnz offset.
+
+%macro TooConditionalBitBranch 0
+  ; Stresses ARM64's tbz/tbnz branch target of +-32KB.
+  jmp %%top
+  %%top:
+
+  lea rax, [rel data]
+  mov rbx, 1
+  %rep 2000
+    add qword [rel data], rbx
+  %endrep
+  lea rax, [%%top]
+  jpe %%top
+%endmacro
+
+mov rax, 0
+cmp rax, 0
+mov rcx, 0
+
+jz long_jump
+
+TooConditionalBitBranch
+
+long_jump:
+mov rax, 1
+hlt
+
+data:
+dq 0, 0, 0, 0

unittests/ASM/FEX_bugs/BranchConditionCheck.asm

@@ -0,0 +1,40 @@
+
+%ifdef CONFIG
+{
+  "RegData": {
+    "RAX": "1"
+  },
+  "Env": { "FEX_MAXINST" : "41010", "FEX_MULTIBLOCK": "1", "FEX_TSOENABLED": "0" }
+}
+%endif
+
+; FEX-Emu had a bug where it tried encoding too large of a conditional branch offset.
+
+%macro TooLargeConditionalBranch 0
+  ; Stresses ARM64's b.cc/cbz/cbnz branch target of +-1MB.
+  jmp %%top
+  %%top:
+
+  lea rax, [rel data]
+  mov rbx, 1
+  %rep 37500
+    add qword [rel data], rbx
+  %endrep
+  lea rax, [%%top]
+  jnz %%top
+%endmacro
+
+mov rax, 0
+cmp rax, 0
+mov rcx, 0
+
+jz long_jump
+
+TooLargeConditionalBranch
+
+long_jump:
+mov rax, 1
+hlt
+
+data:
+dq 0, 0, 0, 0