[PATCH] D156393: [RISCV] Fix getMaxPushPopReg like getLibCallID

[Jim Lin via Phabricator via llvm-commits]

Jim created this revision.
Herald added subscribers: jobnoorman, luke, VincentWu, vkmr, frasercrmck, luismarques, apazos, sameer.abuasal, s.egerton, benna, psnobl, jocewei, PkmX, the_o, brucehoult, MartinMosbeck, rogfer01, edward-jones, zzheng, jrtc27, shiva0217, kito-cheng, niosHD, sabuasal, simoncook, johnrusso, rbar, asb, hiraditya, arichardson.
Herald added a project: All.
Jim requested review of this revision.
Herald added subscribers: llvm-commits, wangpc, eopXD, MaskRay.
Herald added a project: LLVM.

Remove PGPR register class, if saved gpr is in ra, s0, ..., s11,
frame index would be assigned a negative number (-1 for ra, -2 for s0, ...)
by RISCVRegisterInfo::hasReservedSpillSlot like save/restore libcalls.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D156393

Files:
  llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
  llvm/lib/Target/RISCV/RISCVRegisterInfo.cpp
  llvm/lib/Target/RISCV/RISCVRegisterInfo.td


Index: llvm/lib/Target/RISCV/RISCVRegisterInfo.td
===================================================================
--- llvm/lib/Target/RISCV/RISCVRegisterInfo.td
+++ llvm/lib/Target/RISCV/RISCVRegisterInfo.td
@@ -165,15 +165,6 @@
 def SR07 : GPRRegisterClass<(add (sequence "X%u", 8, 9),
                                  (sequence "X%u", 18, 23))>;
 
-// Registers saveable by PUSH/POP instruction in Zcmp extension
-def PGPR : RegisterClass<"RISCV", [XLenVT], 32, (add
-    (sequence "X%u", 8, 9),
-    (sequence "X%u", 18, 27),
-    X1
-  )> {
-  let RegInfos = XLenRI;
-}
-
 // Floating point registers
 let RegAltNameIndices = [ABIRegAltName] in {
   def F0_H  : RISCVReg16<0, "f0", ["ft0"]>, DwarfRegNum<[32]>;
Index: llvm/lib/Target/RISCV/RISCVRegisterInfo.cpp
===================================================================
--- llvm/lib/Target/RISCV/RISCVRegisterInfo.cpp
+++ llvm/lib/Target/RISCV/RISCVRegisterInfo.cpp
@@ -132,7 +132,7 @@
 }
 
 // Frame indexes representing locations of CSRs which are given a fixed location
-// by save/restore libcalls.
+// by save/restore libcalls or Zcmp Push/Pop.
 static const std::pair<unsigned, int> FixedCSRFIMap[] = {
   {/*ra*/  RISCV::X1,   -1},
   {/*s0*/  RISCV::X8,   -2},
Index: llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
===================================================================
--- llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
+++ llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
@@ -267,9 +267,10 @@
   Register MaxPushPopReg = RISCV::NoRegister;
   PushPopRegs = 0;
   for (auto &CS : CSI) {
-    Register Reg = CS.getReg();
-    if (RISCV::PGPRRegClass.contains(Reg)) {
-      MaxPushPopReg = std::max(MaxPushPopReg.id(), Reg.id());
+    // RISCVRegisterInfo::hasReservedSpillSlot assigns negative frame indexes to
+    // registers which can be saved by Push.
+    if (CS.getFrameIdx() < 0) {
+      MaxPushPopReg = std::max(MaxPushPopReg.id(), CS.getReg().id());
       PushPopRegs += 1;
     }
   }


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D156393.544607.patch
Type: text/x-patch
Size: 1981 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20230727/33cf96c3/attachment.bin>