[llvm] r335594 - ARM: correctly decode VFP instructions following unpredictable t2IT

[Tim Northover via llvm-commits]

Author: tnorthover
Date: Tue Jun 26 04:39:20 2018
New Revision: 335594

URL: http://llvm.org/viewvc/llvm-project?rev=335594&view=rev
Log:
ARM: correctly decode VFP instructions following unpredictable t2IT

When the condition code for an IT instruction is "AL" we get strange "15"
predicates on subsequent instructions. These are dealt with for most
instructions by treating them as "ARMCC::AL", but VFP takes a different path
which didn't have this code.

Modified:
    llvm/trunk/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
    llvm/trunk/test/MC/Disassembler/ARM/invalid-IT-CC15.txt

Modified: llvm/trunk/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/Disassembler/ARMDisassembler.cpp?rev=335594&r1=335593&r2=335594&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (original)
+++ llvm/trunk/lib/Target/ARM/Disassembler/ARMDisassembler.cpp Tue Jun 26 04:39:20 2018
@@ -659,6 +659,8 @@ ThumbDisassembler::AddThumbPredicate(MCI
 void ThumbDisassembler::UpdateThumbVFPPredicate(MCInst &MI) const {
   unsigned CC;
   CC = ITBlock.getITCC();
+  if (CC == 0xF)
+    CC = ARMCC::AL;
   if (ITBlock.instrInITBlock())
     ITBlock.advanceITState();
 

Modified: llvm/trunk/test/MC/Disassembler/ARM/invalid-IT-CC15.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/Disassembler/ARM/invalid-IT-CC15.txt?rev=335594&r1=335593&r2=335594&view=diff
==============================================================================
--- llvm/trunk/test/MC/Disassembler/ARM/invalid-IT-CC15.txt (original)
+++ llvm/trunk/test/MC/Disassembler/ARM/invalid-IT-CC15.txt Tue Jun 26 04:39:20 2018
@@ -1,4 +1,4 @@
-# RUN: llvm-mc --disassemble %s -triple=thumbv7-unknown-unknown 2>&1 | grep und
+# RUN: llvm-mc --disassemble %s -triple=thumbv7-unknown-unknown 2>&1 | FileCheck %s
 # rdar://10841671
 
 0xe3 0xbf
@@ -11,8 +11,8 @@
 # above sequence of junk bytes and not allowing the disassembler to abort on
 # printing the final instruction in this list.
 # 
-#	ittte	al
-#	vldr	d19, [pc, #388]
-#	vsub.f64	d17, d17, d16
-#	vadd.f64	d18, d18, d19
-#	vldr<und>	d16, [pc, #384]
+# CHECK: ittte	al
+# CHECK: vldr	d19, [pc, #388]
+# CHECK: vsub.f64	d17, d17, d16
+# CHECK: vadd.f64	d18, d18, d19
+# CHECK: vldr	d16, [pc, #384]