[ms] [X86] Use "P" modifier on operands to call instructions in inline X86 assembly.

Summary:
This is documented as the appropriate template modifier for call operands.
Fixes PR44272, and adds a regression test.

Also adds support for operand modifiers in Intel-style inline assembly.

Reviewers: rnk

Reviewed By: rnk

Subscribers: merge_guards_bot, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D71677

1 files changed, 33 insertions, 4 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
index 420df26a2b8..a0179539533 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
@@ -207,11 +207,17 @@ static void EmitMSInlineAsmStr(const char *AsmStr, const MachineInstr *MI,
       }
       if (Done) break;
 
+      bool HasCurlyBraces = false;
+      if (*LastEmitted == '{') {     // ${variable}
+        ++LastEmitted;               // Consume '{' character.
+        HasCurlyBraces = true;
+      }
+
       // If we have ${:foo}, then this is not a real operand reference, it is a
       // "magic" string reference, just like in .td files.  Arrange to call
       // PrintSpecial.
-      if (LastEmitted[0] == '{' && LastEmitted[1] == ':') {
-        LastEmitted += 2;
+      if (HasCurlyBraces && LastEmitted[0] == ':') {
+        ++LastEmitted;
         const char *StrStart = LastEmitted;
         const char *StrEnd = strchr(StrStart, '}');
         if (!StrEnd)
@@ -238,6 +244,27 @@ static void EmitMSInlineAsmStr(const char *AsmStr, const MachineInstr *MI,
         report_fatal_error("Invalid $ operand number in inline asm string: '" +
                            Twine(AsmStr) + "'");
 
+      char Modifier[2] = { 0, 0 };
+
+      if (HasCurlyBraces) {
+        // If we have curly braces, check for a modifier character.  This
+        // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
+        if (*LastEmitted == ':') {
+          ++LastEmitted;    // Consume ':' character.
+          if (*LastEmitted == 0)
+            report_fatal_error("Bad ${:} expression in inline asm string: '" +
+                               Twine(AsmStr) + "'");
+
+          Modifier[0] = *LastEmitted;
+          ++LastEmitted;    // Consume modifier character.
+        }
+
+        if (*LastEmitted != '}')
+          report_fatal_error("Bad ${} expression in inline asm string: '" +
+                             Twine(AsmStr) + "'");
+        ++LastEmitted;    // Consume '}' character.
+      }
+
       // Okay, we finally have a value number.  Ask the target to print this
       // operand!
       unsigned OpNo = InlineAsm::MIOp_FirstOperand;
@@ -262,9 +289,11 @@ static void EmitMSInlineAsmStr(const char *AsmStr, const MachineInstr *MI,
         ++OpNo;  // Skip over the ID number.
 
         if (InlineAsm::isMemKind(OpFlags)) {
-          Error = AP->PrintAsmMemoryOperand(MI, OpNo, /*Modifier*/ nullptr, OS);
+          Error = AP->PrintAsmMemoryOperand(
+              MI, OpNo, Modifier[0] ? Modifier : nullptr, OS);
         } else {
-          Error = AP->PrintAsmOperand(MI, OpNo, /*Modifier*/ nullptr, OS);
+          Error = AP->PrintAsmOperand(MI, OpNo,
+                                      Modifier[0] ? Modifier : nullptr, OS);
         }
       }
       if (Error) {