[ARMv8] Prevent generation of deprecated IT blocks on ARMv8 in Thumb mode.

IT blocks can only be one instruction lonf, and can only contain a subset of
the 16 instructions.

Patch by Artyom Skrobov!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190309 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 43 insertions, 0 deletions

diff --git a/test/CodeGen/Thumb2/v8_IT_4.ll b/test/CodeGen/Thumb2/v8_IT_4.ll
new file mode 100644
index 0000000000..45c79f430f
--- /dev/null
+++ b/test/CodeGen/Thumb2/v8_IT_4.ll
@@ -0,0 +1,43 @@
+; RUN: llc < %s -mtriple=thumbv8-eabi -float-abi=hard | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv8-eabi -float-abi=hard -regalloc=basic | FileCheck %s
+
+%"struct.__gnu_cxx::__normal_iterator<char*,std::basic_string<char, std::char_traits<char>, std::allocator<char> > >" = type { i8* }
+%"struct.__gnu_cxx::new_allocator<char>" = type <{ i8 }>
+%"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >" = type { %"struct.__gnu_cxx::__normal_iterator<char*,std::basic_string<char, std::char_traits<char>, std::allocator<char> > >" }
+%"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >::_Rep" = type { %"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >::_Rep_base" }
+%"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >::_Rep_base" = type { i32, i32, i32 }
+
+
+define weak arm_aapcs_vfpcc i32 @_ZNKSs7compareERKSs(%"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >"* %this, %"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >"* %__str) {
+; CHECK-LABEL: _ZNKSs7compareERKSs:
+; CHECK:      cbnz	r0,
+; CHECK-NEXT: %bb
+; CHECK-NEXT: sub{{(.w)?}} r0, r{{[0-9]+}}, r{{[0-9]+}}
+; CHECK-NEXT: %bb1
+; CHECK-NEXT: pop.w
+entry:
+  %0 = tail call arm_aapcs_vfpcc  i32 @_ZNKSs4sizeEv(%"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >"* %this) ; <i32> [#uses=3]
+  %1 = tail call arm_aapcs_vfpcc  i32 @_ZNKSs4sizeEv(%"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >"* %__str) ; <i32> [#uses=3]
+  %2 = icmp ult i32 %1, %0                        ; <i1> [#uses=1]
+  %3 = select i1 %2, i32 %1, i32 %0               ; <i32> [#uses=1]
+  %4 = tail call arm_aapcs_vfpcc  i8* @_ZNKSs7_M_dataEv(%"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >"* %this) ; <i8*> [#uses=1]
+  %5 = tail call arm_aapcs_vfpcc  i8* @_ZNKSs4dataEv(%"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >"* %__str) ; <i8*> [#uses=1]
+  %6 = tail call arm_aapcs_vfpcc  i32 @memcmp(i8* %4, i8* %5, i32 %3) nounwind readonly ; <i32> [#uses=2]
+  %7 = icmp eq i32 %6, 0                          ; <i1> [#uses=1]
+  br i1 %7, label %bb, label %bb1
+
+bb:                                               ; preds = %entry
+  %8 = sub i32 %0, %1                             ; <i32> [#uses=1]
+  ret i32 %8
+
+bb1:                                              ; preds = %entry
+  ret i32 %6
+}
+
+declare arm_aapcs_vfpcc i32 @memcmp(i8* nocapture, i8* nocapture, i32) nounwind readonly
+
+declare arm_aapcs_vfpcc i32 @_ZNKSs4sizeEv(%"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >"* %this)
+
+declare arm_aapcs_vfpcc i8* @_ZNKSs7_M_dataEv(%"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >"* %this)
+
+declare arm_aapcs_vfpcc i8* @_ZNKSs4dataEv(%"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >"* %this)