[llvm] 2218587 - MIPS: Support isLegalICmpImmediate and isLegalAddImmediate (#133400)

[via llvm-commits]

Author: YunQiang Su
Date: 2025-03-28T23:03:52+08:00
New Revision: 2218587b5b131bb8ed57c3e6c7a5c0c589493300

URL: https://github.com/llvm/llvm-project/commit/2218587b5b131bb8ed57c3e6c7a5c0c589493300
DIFF: https://github.com/llvm/llvm-project/commit/2218587b5b131bb8ed57c3e6c7a5c0c589493300.diff

LOG: MIPS: Support isLegalICmpImmediate and isLegalAddImmediate (#133400)

Set it to true only if isInt<16>.
By default implemention defines them to true always. For most cases,
MIPS uses 16bit IMM, and for microMIPS, ICMP and ADDiu have 16bit IMM
flavors.

Added: 
    

Modified: 
    llvm/lib/Target/Mips/MipsISelLowering.cpp
    llvm/lib/Target/Mips/MipsISelLowering.h

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/Mips/MipsISelLowering.cpp b/llvm/lib/Target/Mips/MipsISelLowering.cpp
index bd65431b475d0..fa8a4704730cf 100644
--- a/llvm/lib/Target/Mips/MipsISelLowering.cpp
+++ b/llvm/lib/Target/Mips/MipsISelLowering.cpp
@@ -4474,6 +4474,14 @@ bool MipsTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT,
   return Imm.isZero();
 }
 
+bool MipsTargetLowering::isLegalICmpImmediate(int64_t Imm) const {
+  return isInt<16>(Imm);
+}
+
+bool MipsTargetLowering::isLegalAddImmediate(int64_t Imm) const {
+  return isInt<16>(Imm);
+}
+
 unsigned MipsTargetLowering::getJumpTableEncoding() const {
   if (!isPositionIndependent())
     return MachineJumpTableInfo::EK_BlockAddress;

diff  --git a/llvm/lib/Target/Mips/MipsISelLowering.h b/llvm/lib/Target/Mips/MipsISelLowering.h
index 5bd7b09ded45b..9885ab894d6f2 100644
--- a/llvm/lib/Target/Mips/MipsISelLowering.h
+++ b/llvm/lib/Target/Mips/MipsISelLowering.h
@@ -706,6 +706,9 @@ class TargetRegisterClass;
     bool isFPImmLegal(const APFloat &Imm, EVT VT,
                       bool ForCodeSize) const override;
 
+    bool isLegalICmpImmediate(int64_t Imm) const override;
+    bool isLegalAddImmediate(int64_t Imm) const override;
+
     unsigned getJumpTableEncoding() const override;
     SDValue getPICJumpTableRelocBase(SDValue Table,
                                      SelectionDAG &DAG) const override;