fixup! Accept [-128,255]

Author: topperc

llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp

@@ -808,7 +808,6 @@ struct RISCVOperand final : public MCParsedAsmOperand {
 
   bool isSImm5() const { return isSImm<5>(); }
   bool isSImm6() const { return isSImm<6>(); }
-  bool isSImm8() const { return isSImm<8>(); }
   bool isSImm10() const { return isSImm<10>(); }
   bool isSImm11() const { return isSImm<11>(); }
   bool isSImm16() const { return isSImm<16>(); }
@@ -904,6 +903,7 @@ struct RISCVOperand final : public MCParsedAsmOperand {
            VK == RISCV::S_QC_ABS20;
   }
 
+  bool isSImm8Unsigned() const { return isSImm<8>() || isUImm<8>(); }
   bool isSImm10Unsigned() const { return isSImm<10>() || isUImm<10>(); }
 
   bool isUImm20LUI() const {
@@ -1200,6 +1200,14 @@ struct RISCVOperand final : public MCParsedAsmOperand {
     addExpr(Inst, getImm(), isRV64Imm());
   }
 
+  void addSImm8UnsignedOperands(MCInst &Inst, unsigned N) const {
+    assert(N == 1 && "Invalid number of operands!");
+    int64_t Imm;
+    [[maybe_unused]] bool IsConstant = evaluateConstantImm(getImm(), Imm);
+    assert(IsConstant);
+    Inst.addOperand(MCOperand::createImm(SignExtend64<8>(Imm)));
+  }
+
   void addSImm10UnsignedOperands(MCInst &Inst, unsigned N) const {
     assert(N == 1 && "Invalid number of operands!");
     int64_t Imm;
@@ -1548,9 +1556,9 @@ bool RISCVAsmParser::matchAndEmitInstruction(SMLoc IDLoc, unsigned &Opcode,
     return generateImmOutOfRangeError(
         Operands, ErrorInfo, 0, (1 << 9) - 8,
         "immediate must be a multiple of 8 bytes in the range");
-  case Match_InvalidSImm8:
+  case Match_InvalidSImm8Unsigned:
     return generateImmOutOfRangeError(Operands, ErrorInfo, -(1 << 7),
-                                      (1 << 7) - 1);
+                                      (1 << 8) - 1);
   case Match_InvalidSImm10:
     return generateImmOutOfRangeError(Operands, ErrorInfo, -(1 << 9),
                                       (1 << 9) - 1);

llvm/lib/Target/RISCV/RISCVInstrInfoP.td

@@ -18,9 +18,27 @@
 // Operand and SDNode transformation definitions.
 //===----------------------------------------------------------------------===//
 
-def simm8 : RISCVSImmOp<8>;
 def simm10 : RISCVSImmOp<10>;
 
+def SImm8UnsignedAsmOperand : SImmAsmOperand<8, "Unsigned"> {
+  let RenderMethod = "addSImm8UnsignedOperands";
+}
+
+// A 8-bit signed immediate allowing range [-128, 255]
+// but represented as [-128, 255].
+def simm8_unsigned : RISCVOp {
+  let ParserMatchClass = SImm8UnsignedAsmOperand;
+  let EncoderMethod = "getImmOpValue";
+  let DecoderMethod = "decodeSImmOperand<8>";
+  let OperandType = "OPERAND_SIMM10";
+  let MCOperandPredicate = [{
+    int64_t Imm;
+    if (!MCOp.evaluateAsConstantImm(Imm))
+      return false;
+    return isInt<8>(Imm);
+  }];
+}
+
 def SImm10UnsignedAsmOperand : SImmAsmOperand<10, "Unsigned"> {
   let RenderMethod = "addSImm10UnsignedOperands";
 }
@@ -76,8 +94,8 @@ class PLUI_i<bits<7> funct7, string opcodestr>
 
 let hasSideEffects = 0, mayLoad = 0, mayStore = 0 in
 class PLI_B_i<bits<8> funct8, string opcodestr>
-    : RVInst<(outs GPR:$rd), (ins simm8:$imm8), opcodestr, "$rd, $imm8", [],
-             InstFormatOther> {
+    : RVInst<(outs GPR:$rd), (ins simm8_unsigned:$imm8), opcodestr,
+             "$rd, $imm8", [], InstFormatOther> {
   bits<8> imm8;
   bits<5> rd;
 

llvm/test/MC/RISCV/rv32p-invalid.s

@@ -4,7 +4,7 @@
 # Imm overflow
 pli.h a0, 0x400 # CHECK: :[[@LINE]]:11: error: immediate must be an integer in the range [-512, 511]
 plui.h a1, 0x400 # CHECK: :[[@LINE]]:12: error: immediate must be an integer in the range [-512, 1023]
-pli.b a0, 0x200 # CHECK: :[[@LINE]]:11: error: immediate must be an integer in the range [-128, 127]
+pli.b a0, 0x200 # CHECK: :[[@LINE]]:11: error: immediate must be an integer in the range [-128, 255]
 
 pslli.b a6, a7, 100 # CHECK: :[[@LINE]]:17: error: immediate must be an integer in the range [0, 7]
 pslli.h ra, sp, 100 # CHECK: :[[@LINE]]:17: error: immediate must be an integer in the range [0, 15]

llvm/test/MC/RISCV/rv64p-valid.s

@@ -82,6 +82,9 @@ pli.b a6, 6
 # CHECK-ASM-AND-OBJ: pli.b a6, -1
 # CHECK-ASM: encoding: [0x1b,0x28,0xff,0xb4]
 pli.b a6, -1
+# CHECK-ASM-AND-OBJ: pli.b a6, -1
+# CHECK-ASM: encoding: [0x1b,0x28,0xff,0xb4]
+pli.b a6, 255
 # CHECK-ASM-AND-OBJ: psext.h.b t3, a2
 # CHECK-ASM: encoding: [0x1b,0x2e,0x46,0xe0]
 psext.h.b t3, a2