[PATCH] D37374: [PATCH][ARM] Enable the use of SVC anywhere in an IT block

[Andre Vieira via Phabricator via llvm-commits]

avieira updated this revision to Diff 113531.
avieira added a comment.

I moved the check into the existing isCall check and updated the comments.

As for checking whether isCall makes sense for SVC, I think that should be done separately? I don't know exactly what other implications that may have.


https://reviews.llvm.org/D37374

Files:
  lib/Target/ARM/AsmParser/ARMAsmParser.cpp
  test/MC/ARM/basic-thumb2-instructions.s


Index: test/MC/ARM/basic-thumb2-instructions.s
===================================================================
--- test/MC/ARM/basic-thumb2-instructions.s
+++ test/MC/ARM/basic-thumb2-instructions.s
@@ -3113,12 +3113,18 @@
         svceq #255
         it ne
         swine #33
+        itt eq
+        svceq #0
+        svceq #1
 
 @ CHECK: svc	#0                      @ encoding: [0x00,0xdf]
 @ CHECK: it	eq                      @ encoding: [0x08,0xbf]
 @ CHECK: svceq	#255                    @ encoding: [0xff,0xdf]
 @ CHECK: it	ne                      @ encoding: [0x18,0xbf]
 @ CHECK: svcne	#33                     @ encoding: [0x21,0xdf]
+@ CHECK: itt    eq                      @ encoding: [0x04,0xbf]
+@ CHECK: svceq  #0                      @ encoding: [0x00,0xdf]
+@ CHECK: svceq  #1                      @ encoding: [0x01,0xdf]
 
 
 @------------------------------------------------------------------------------
Index: lib/Target/ARM/AsmParser/ARMAsmParser.cpp
===================================================================
--- lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -8721,11 +8721,13 @@
 // Returns true if Inst is unpredictable if it is in and IT block, but is not
 // the last instruction in the block.
 bool ARMAsmParser::isITBlockTerminator(MCInst &Inst) const {
+
   const MCInstrDesc &MCID = MII.get(Inst.getOpcode());
 
-  // All branch & call instructions terminate IT blocks.
-  if (MCID.isTerminator() || MCID.isCall() || MCID.isReturn() ||
-      MCID.isBranch() || MCID.isIndirectBranch())
+  // All branch & call instructions terminate IT blocks with the exception of
+  // SVC.
+  if (MCID.isTerminator() || (MCID.isCall() && Inst.getOpcode() != ARM::tSVC) ||
+      MCID.isReturn() || MCID.isBranch() || MCID.isIndirectBranch())
     return true;
 
   // Any arithmetic instruction which writes to the PC also terminates the IT


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