Fix the encoding of the armv7m (MClass) for MSR APSR writes which was missing

[oota-llvm.git] / lib / Target / ARM / AsmParser / ARMAsmParser.cpp

diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 88659796705dcfd4b6be6450e28519fd404d593e..00e7f6e8fb990fb509b17cffd21eda8a33ba1201 100644 (file)
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -3324,10 +3324,35 @@ parseMSRMaskOperand(SmallVectorImpl<MCParsedAsmOperand*> &Operands) {
     // See ARMv6-M 10.1.1
     std::string Name = Mask.lower();
     unsigned FlagsVal = StringSwitch<unsigned>(Name)
-      .Case("apsr", 0)
-      .Case("iapsr", 1)
-      .Case("eapsr", 2)
-      .Case("xpsr", 3)
+      // Note: in the documentation:
+      //  ARM deprecates using MSR APSR without a _<bits> qualifier as an alias
+      //  for MSR APSR_nzcvq.
+      // but we do make it an alias here.  This is so to get the "mask encoding"
+      // bits correct on MSR APSR writes.
+      //
+      // FIXME: Note the 0xc00 "mask encoding" bits version of the registers
+      // should really only be allowed when writing a special register.  Note
+      // they get dropped in the MRS instruction reading a special register as
+      // the SYSm field is only 8 bits.
+      //
+      // FIXME: the _g and _nzcvqg versions are only allowed if the processor
+      // includes the DSP extension but that is not checked.
+      .Case("apsr", 0x800)
+      .Case("apsr_nzcvq", 0x800)
+      .Case("apsr_g", 0x400)
+      .Case("apsr_nzcvqg", 0xc00)
+      .Case("iapsr", 0x801)
+      .Case("iapsr_nzcvq", 0x801)
+      .Case("iapsr_g", 0x401)
+      .Case("iapsr_nzcvqg", 0xc01)
+      .Case("eapsr", 0x802)
+      .Case("eapsr_nzcvq", 0x802)
+      .Case("eapsr_g", 0x402)
+      .Case("eapsr_nzcvqg", 0xc02)
+      .Case("xpsr", 0x803)
+      .Case("xpsr_nzcvq", 0x803)
+      .Case("xpsr_g", 0x403)
+      .Case("xpsr_nzcvqg", 0xc03)
       .Case("ipsr", 5)
       .Case("epsr", 6)
       .Case("iepsr", 7)