[release/9.0] Fix encoding for certain k-mask instructions (#107249)

* Fix encoding for certain k-mask instructions * Update instr.h * Update Runtime_107146.cs * Update src/coreclr/jit/emitxarch.cpp Co-authored-by: Jakob Botsch Nielsen <Jakob.botsch.nielsen@gmail.com> --------- Co-authored-by: EgorBo <egorbo@gmail.com> Co-authored-by: Jakob Botsch Nielsen <Jakob.botsch.nielsen@gmail.com> Co-authored-by: Jeff Schwartz <jeffschw@microsoft.com>
dotnet · Sep 4, 2024 · 48fd63c · 48fd63c
1 parent 31528d0
commit 48fd63c
Show file tree

Hide file tree

Showing 6 changed files with 104 additions and 29 deletions.
diff --git a/src/coreclr/jit/emitxarch.cpp b/src/coreclr/jit/emitxarch.cpp
@@ -49,6 +49,23 @@ bool emitter::IsKInstruction(instruction ins)
     return (flags & KInstruction) != 0;
 }
 
+//------------------------------------------------------------------------
+// IsKInstructionWithLBit: Does this instruction require K register and
+//    LBIT_IN_3BYTE_VEX_PREFIX bit.
+//
+// Arguments:
+//    ins - The instruction to check.
+//
+// Returns:
+//    `true` if this instruction requires K register and
+//    LBIT_IN_3BYTE_VEX_PREFIX bit.
+//
+bool emitter::IsKInstructionWithLBit(instruction ins)
+{
+    insFlags flags = CodeGenInterface::instInfo[ins];
+    return (flags & KInstructionWithLBit) != 0;
+}
+
 bool emitter::IsAVXOnlyInstruction(instruction ins)
 {
     return (ins >= INS_FIRST_AVX_INSTRUCTION) && (ins <= INS_LAST_AVX_INSTRUCTION);
@@ -1495,7 +1512,7 @@ emitter::code_t emitter::AddVexPrefix(instruction ins, code_t code, emitAttr att
 
     code |= DEFAULT_3BYTE_VEX_PREFIX;
 
-    if (attr == EA_32BYTE)
+    if ((attr == EA_32BYTE) || IsKInstructionWithLBit(ins))
     {
         // Set L bit to 1 in case of instructions that operate on 256-bits.
         code |= LBIT_IN_3BYTE_VEX_PREFIX;

diff --git a/src/coreclr/jit/emitxarch.h b/src/coreclr/jit/emitxarch.h
@@ -113,6 +113,7 @@ static bool IsPermuteVar2xInstruction(instruction ins);
 static bool IsAVXVNNIInstruction(instruction ins);
 static bool IsBMIInstruction(instruction ins);
 static bool IsKInstruction(instruction ins);
+static bool IsKInstructionWithLBit(instruction ins);
 
 static regNumber getBmiRegNumber(instruction ins);
 static regNumber getSseShiftRegNumber(instruction ins);

diff --git a/src/coreclr/jit/instr.h b/src/coreclr/jit/instr.h
@@ -213,9 +213,10 @@ enum insFlags : uint64_t
     Encoding_EVEX  = 1ULL << 40,
 
     KInstruction = 1ULL << 41,
+    KInstructionWithLBit = 1ULL << 42,
 
     // EVEX feature: embedded broadcast
-    INS_Flags_EmbeddedBroadcastSupported = 1ULL << 42,
+    INS_Flags_EmbeddedBroadcastSupported = 1ULL << 43,
 
     //  TODO-Cleanup:  Remove this flag and its usage from TARGET_XARCH
     INS_FLAGS_DONT_CARE = 0x00ULL,