[RISCV] Pass sign-extended value to isInt check in expandMul (#150211)

In the `isInt` check that was added in #147661 we were passing the
zero-extended `uint64_t` value instead of the sign-extended one.

(cherry picked from commit d3937e2)

Author: svs-quic

llvm/lib/Target/RISCV/RISCVISelLowering.cpp

@@ -16013,7 +16013,7 @@ static SDValue expandMul(SDNode *N, SelectionDAG &DAG,
   uint64_t MulAmt = CNode->getZExtValue();
 
   // Don't do this if the Xqciac extension is enabled and the MulAmt in simm12.
-  if (Subtarget.hasVendorXqciac() && isInt<12>(MulAmt))
+  if (Subtarget.hasVendorXqciac() && isInt<12>(CNode->getSExtValue()))
     return SDValue();
 
   const bool HasShlAdd = Subtarget.hasStdExtZba() ||

llvm/test/CodeGen/RISCV/xqciac.ll

@@ -463,3 +463,30 @@ entry:
   %add = add nsw i32 %shlc1, %shlc2
   ret i32 %add
 }
+
+define i32 @testmuliaddnegimm(i32 %a) {
+; RV32IM-LABEL: testmuliaddnegimm:
+; RV32IM:       # %bb.0:
+; RV32IM-NEXT:    slli a1, a0, 1
+; RV32IM-NEXT:    add a0, a1, a0
+; RV32IM-NEXT:    li a1, 3
+; RV32IM-NEXT:    sub a0, a1, a0
+; RV32IM-NEXT:    ret
+;
+; RV32IMXQCIAC-LABEL: testmuliaddnegimm:
+; RV32IMXQCIAC:       # %bb.0:
+; RV32IMXQCIAC-NEXT:    li a1, 3
+; RV32IMXQCIAC-NEXT:    qc.muliadd a1, a0, -3
+; RV32IMXQCIAC-NEXT:    mv a0, a1
+; RV32IMXQCIAC-NEXT:    ret
+;
+; RV32IZBAMXQCIAC-LABEL: testmuliaddnegimm:
+; RV32IZBAMXQCIAC:       # %bb.0:
+; RV32IZBAMXQCIAC-NEXT:    li a1, 3
+; RV32IZBAMXQCIAC-NEXT:    qc.muliadd a1, a0, -3
+; RV32IZBAMXQCIAC-NEXT:    mv a0, a1
+; RV32IZBAMXQCIAC-NEXT:    ret
+  %mul = mul i32 %a, -3
+  %add = add i32 %mul, 3
+  ret i32 %add
+}