[x86][MC] Fix data32 push.

Author: daym

llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp

@@ -4538,14 +4538,26 @@ bool X86AsmParser::matchAndEmitIntelInstruction(
     if (X86Op->isImm()) {
       // If it's not a constant fall through and let remainder take care of it.
       const auto *CE = dyn_cast<MCConstantExpr>(X86Op->getImm());
-      unsigned Size = getPointerWidth();
+      // Determine the size. Prioritize the ForcedDataPrefix flag if it was set
+      // by a 'data32' prefix. Otherwise, fall back to the pointer width of the
+      // current mode.
+      unsigned Size = (ForcedDataPrefix == X86::Is32Bit)   ? 32
+                      : (ForcedDataPrefix == X86::Is16Bit) ? 16
+                                                           : getPointerWidth();
+      ForcedDataPrefix = 0;
       if (CE &&
           (isIntN(Size, CE->getValue()) || isUIntN(Size, CE->getValue()))) {
         SmallString<16> Tmp;
         Tmp += Base;
-        Tmp += (is64BitMode())
-                   ? "q"
-                   : (is32BitMode()) ? "l" : (is16BitMode()) ? "w" : " ";
+        // Append the suffix corresponding to the determined size.
+        if (Size == 64)
+          Tmp += "q";
+        else if (Size == 32)
+          Tmp += "l";
+        else if (Size == 16)
+          Tmp += "w";
+        else
+          Tmp += " ";
         Op.setTokenValue(Tmp);
         // Do match in ATT mode to allow explicit suffix usage.
         Match.push_back(MatchInstruction(Operands, Inst, ErrorInfo,

llvm/test/MC/X86/x86-16-intel.s

@@ -0,0 +1,13 @@
+// RUN: llvm-mc -triple i386-unknown-unknown-code16 --x86-asm-syntax=intel --show-encoding %s | FileCheck %s
+
+// CHECK: pushl $8
+// CHECK: encoding: [0x66,0x6a,0x08]
+          data32 push 8
+
+// CHECK: pushw $8
+// CHECK: encoding: [0x6a,0x08]
+          push 8
+
+// CHECK: lretl
+// CHECK: encoding: [0x66,0xcb]
+          data32 retf

llvm/test/MC/X86/x86-16.s

@@ -1060,3 +1060,15 @@ xresldtrk
 // CHECK:  encoding: [0x66,0x8b,0x1e,A,A]
 // CHECK:  fixup A - offset: 3, value: nearer, kind: FK_Data_2
 movl    nearer, %ebx
+
+// CHECK: pushl $8
+// CHECK:  encoding: [0x66,0x6a,0x08]
+data32 push $8
+
+// CHECK: pushl $8
+// CHECK:  encoding: [0x66,0x6a,0x08]
+pushl $8
+
+// CHECK: pushw $8
+// CHECK:  encoding: [0x6a,0x08]
+push $8