Fix for PR18921, "vmov" part.

Added support for bytes replication feature, so it could be GAS compatible.

E.g. instructions below:
"vmov.i32 d0, 0xffffffff"
"vmvn.i32 d0, 0xabababab"
"vmov.i32 d0, 0xabababab"
"vmov.i16 d0, 0xabab"
are incorrect, but we could deal with such cases.

For first one we should emit:
"vmov.i8 d0, 0xff"
For second one ("vmvn"):
"vmov.i8 d0, 0x54"
For last two instructions it should emit:
"vmov.i8 d0, 0xab"

P.S.: In ARMAsmParser.cpp I have also fixed few nearby style issues in old code.
Just for keeping method bodies in harmony with themselves.

llvm-svn: 207080

1 files changed, 61 insertions, 4 deletions

diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index f661d8a4beb..71b558d46bb 100644
--- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -1610,7 +1610,10 @@ public:
   }
 
   bool isNEONi16splat() const {
-    if (!isImm()) return false;
+    if (isNEONByteReplicate(2))
+      return false; // Leave that for bytes replication and forbid by default.
+    if (!isImm())
+      return false;
     const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(getImm());
     // Must be a constant.
     if (!CE) return false;
@@ -1620,7 +1623,10 @@ public:
   }
 
   bool isNEONi32splat() const {
-    if (!isImm()) return false;
+    if (isNEONByteReplicate(4))
+      return false; // Leave that for bytes replication and forbid by default.
+    if (!isImm())
+      return false;
     const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(getImm());
     // Must be a constant.
     if (!CE) return false;
@@ -1632,11 +1638,36 @@ public:
       (Value >= 0x01000000 && Value <= 0xff000000);
   }
 
+  bool isNEONByteReplicate(unsigned NumBytes) const {
+    if (!isImm())
+      return false;
+    const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(getImm());
+    // Must be a constant.
+    if (!CE)
+      return false;
+    int64_t Value = CE->getValue();
+    if (!Value)
+      return false; // Don't bother with zero.
+
+    unsigned char B = Value & 0xff;
+    for (unsigned i = 1; i < NumBytes; ++i) {
+      Value >>= 8;
+      if ((Value & 0xff) != B)
+        return false;
+    }
+    return true;
+  }
+  bool isNEONi16ByteReplicate() const { return isNEONByteReplicate(2); }
+  bool isNEONi32ByteReplicate() const { return isNEONByteReplicate(4); }
   bool isNEONi32vmov() const {
-    if (!isImm()) return false;
+    if (isNEONByteReplicate(4))
+      return false; // Let it to be classified as byte-replicate case.
+    if (!isImm())
+      return false;
     const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(getImm());
     // Must be a constant.
-    if (!CE) return false;
+    if (!CE)
+      return false;
     int64_t Value = CE->getValue();
     // i32 value with set bits only in one byte X000, 0X00, 00X0, or 000X,
     // for VMOV/VMVN only, 00Xf or 0Xff are also accepted.
@@ -2384,6 +2415,19 @@ public:
     Inst.addOperand(MCOperand::CreateImm(Value));
   }
 
+  void addNEONinvByteReplicateOperands(MCInst &Inst, unsigned N) const {
+    assert(N == 1 && "Invalid number of operands!");
+    // The immediate encodes the type of constant as well as the value.
+    const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(getImm());
+    unsigned Value = CE->getValue();
+    assert((Inst.getOpcode() == ARM::VMOVv8i8 ||
+            Inst.getOpcode() == ARM::VMOVv16i8) &&
+           "All vmvn instructions that wants to replicate non-zero byte "
+           "always must be replaced with VMOVv8i8 or VMOVv16i8.");
+    unsigned B = ((~Value) & 0xff);
+    B |= 0xe00; // cmode = 0b1110
+    Inst.addOperand(MCOperand::CreateImm(B));
+  }
   void addNEONi32vmovOperands(MCInst &Inst, unsigned N) const {
     assert(N == 1 && "Invalid number of operands!");
     // The immediate encodes the type of constant as well as the value.
@@ -2398,6 +2442,19 @@ public:
     Inst.addOperand(MCOperand::CreateImm(Value));
   }
 
+  void addNEONvmovByteReplicateOperands(MCInst &Inst, unsigned N) const {
+    assert(N == 1 && "Invalid number of operands!");
+    // The immediate encodes the type of constant as well as the value.
+    const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(getImm());
+    unsigned Value = CE->getValue();
+    assert((Inst.getOpcode() == ARM::VMOVv8i8 ||
+            Inst.getOpcode() == ARM::VMOVv16i8) &&
+           "All instructions that wants to replicate non-zero byte "
+           "always must be replaced with VMOVv8i8 or VMOVv16i8.");
+    unsigned B = Value & 0xff;
+    B |= 0xe00; // cmode = 0b1110
+    Inst.addOperand(MCOperand::CreateImm(B));
+  }
   void addNEONi32vmovNegOperands(MCInst &Inst, unsigned N) const {
     assert(N == 1 && "Invalid number of operands!");
     // The immediate encodes the type of constant as well as the value.