[PATCH] D88137: [X86] Parse data32 call in .code16 as CALLpcrel32

[Fangrui Song via Phabricator via llvm-commits]

MaskRay created this revision.
MaskRay added reviewers: craig.topper, RKSimon.
Herald added subscribers: llvm-commits, hiraditya.
Herald added a project: LLVM.
MaskRay requested review of this revision.

Used by kexec-tools (PR46942)
In GNU as, tc-i386.c:output_jump uses 4-byte immediate if a data32 prefix is present.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D88137

Files:
  llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
  llvm/test/MC/X86/data-prefix-fail.s
  llvm/test/MC/X86/x86-16.s


Index: llvm/test/MC/X86/x86-16.s
===================================================================
--- llvm/test/MC/X86/x86-16.s
+++ llvm/test/MC/X86/x86-16.s
@@ -546,8 +546,12 @@
 jmp	$0x7ace,$0x7ace
 ljmp	$0x7ace,$0x7ace
 
+// CHECK: calll a
+// CHECK: calll a
 // CHECK: calll a
  calll a
+data32 call a
+data32 callw a
 
 // CHECK:	incb	%al # encoding: [0xfe,0xc0]
 	incb %al
Index: llvm/test/MC/X86/data-prefix-fail.s
===================================================================
--- llvm/test/MC/X86/data-prefix-fail.s
+++ llvm/test/MC/X86/data-prefix-fail.s
@@ -23,3 +23,6 @@
 // 32: encoding: [0x0f,0x01,0x15,0x00,0x00,0x00,0x00]
 // ERR16: error: redundant data16 prefix
 data16 lgdt 0
+
+// ERR16: {{.*}}.s:[[#@LINE+1]]:1: error: redundant data16 prefix
+data16 call 0
Index: llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
===================================================================
--- llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -3012,6 +3012,17 @@
       return Error(NameLoc, "'data32' is not supported in 64-bit mode");
     // Hack to 'data16' for the table lookup.
     PatchedName = "data16";
+
+    if (getLexer().isNot(AsmToken::EndOfStatement)) {
+      StringRef Next = Parser.getTok().getString();
+      // Parse data32 call as calll.
+      if (Next == "call" || Next == "callw") {
+        getLexer().Lex();
+        Name = "calll";
+        PatchedName = Name;
+        isPrefix = false;
+      }
+    }
   }
 
   Operands.push_back(X86Operand::CreateToken(PatchedName, NameLoc));


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