[clang] [clang][bytecode] Implement ia32_{pdep, pext} builtins (PR #110675)

[Timm Baeder via cfe-commits]

https://github.com/tbaederr created https://github.com/llvm/llvm-project/pull/110675

None

>From e57f67c73af56e510943612e4eff651838706b9e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Tue, 1 Oct 2024 15:41:43 +0200
Subject: [PATCH] [clang][bytecode] Implement ia32_{pdep,pext} builtins

---
 clang/lib/AST/ByteCode/InterpBuiltin.cpp | 54 ++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/clang/lib/AST/ByteCode/InterpBuiltin.cpp b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
index 347b23d7b89c46..ebc800623f0d48 100644
--- a/clang/lib/AST/ByteCode/InterpBuiltin.cpp
+++ b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
@@ -1219,6 +1219,48 @@ static bool interp__builtin_ia32_tzcnt(InterpState &S, CodePtr OpPC,
   return true;
 }
 
+static bool interp__builtin_ia32_pdep(InterpState &S, CodePtr OpPC,
+                                      const InterpFrame *Frame,
+                                      const Function *Func,
+                                      const CallExpr *Call) {
+  PrimType ValT = *S.Ctx.classify(Call->getArg(0));
+  PrimType MaskT = *S.Ctx.classify(Call->getArg(1));
+
+  APSInt Val =
+      peekToAPSInt(S.Stk, ValT, align(primSize(ValT)) + align(primSize(MaskT)));
+  APSInt Mask = peekToAPSInt(S.Stk, MaskT);
+
+  unsigned BitWidth = Val.getBitWidth();
+  APInt Result = APInt::getZero(BitWidth);
+  for (unsigned I = 0, P = 0; I != BitWidth; ++I) {
+    if (Mask[I])
+      Result.setBitVal(I, Val[P++]);
+  }
+  pushInteger(S, Result, Call->getType());
+  return true;
+}
+
+static bool interp__builtin_ia32_pext(InterpState &S, CodePtr OpPC,
+                                      const InterpFrame *Frame,
+                                      const Function *Func,
+                                      const CallExpr *Call) {
+  PrimType ValT = *S.Ctx.classify(Call->getArg(0));
+  PrimType MaskT = *S.Ctx.classify(Call->getArg(1));
+
+  APSInt Val =
+      peekToAPSInt(S.Stk, ValT, align(primSize(ValT)) + align(primSize(MaskT)));
+  APSInt Mask = peekToAPSInt(S.Stk, MaskT);
+
+  unsigned BitWidth = Val.getBitWidth();
+  APInt Result = APInt::getZero(BitWidth);
+  for (unsigned I = 0, P = 0; I != BitWidth; ++I) {
+    if (Mask[I])
+      Result.setBitVal(P++, Val[I]);
+  }
+  pushInteger(S, Result, Call->getType());
+  return true;
+}
+
 static bool interp__builtin_os_log_format_buffer_size(InterpState &S,
                                                       CodePtr OpPC,
                                                       const InterpFrame *Frame,
@@ -1832,6 +1874,18 @@ bool InterpretBuiltin(InterpState &S, CodePtr OpPC, const Function *F,
       return false;
     break;
 
+  case clang::X86::BI__builtin_ia32_pdep_si:
+  case clang::X86::BI__builtin_ia32_pdep_di:
+    if (!interp__builtin_ia32_pdep(S, OpPC, Frame, F, Call))
+      return false;
+    break;
+
+  case clang::X86::BI__builtin_ia32_pext_si:
+  case clang::X86::BI__builtin_ia32_pext_di:
+    if (!interp__builtin_ia32_pext(S, OpPC, Frame, F, Call))
+      return false;
+    break;
+
   case Builtin::BI__builtin_os_log_format_buffer_size:
     if (!interp__builtin_os_log_format_buffer_size(S, OpPC, Frame, F, Call))
       return false;