[PATCH] D106134: [RISCV] Make VLEN no greater than 65536.

[Jianjian Guan via Phabricator via llvm-commits]

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

Add constraint of VLEN for RVV v1.0-rc


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D106134

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


Index: llvm/lib/Target/RISCV/RISCVSubtarget.cpp
===================================================================
--- llvm/lib/Target/RISCV/RISCVSubtarget.cpp
+++ llvm/lib/Target/RISCV/RISCVSubtarget.cpp
@@ -109,30 +109,32 @@
   assert(hasStdExtV() && "Tried to get vector length without V support!");
   if (RVVVectorBitsMax == 0)
     return 0;
-  assert(RVVVectorBitsMax >= 128 && isPowerOf2_32(RVVVectorBitsMax) &&
-         "V extension requires vector length to be at least 128 and a power of "
-         "2!");
+  assert(RVVVectorBitsMax >= 128 && RVVVectorBitsMax <= 65536 &&
+         isPowerOf2_32(RVVVectorBitsMax) &&
+         "V extension requires vector length to be in the range of 128 to "
+         "65536 and a power of 2!");
   assert(RVVVectorBitsMax >= RVVVectorBitsMin &&
          "Minimum V extension vector length should not be larger than its "
          "maximum!");
   unsigned Max = std::max(RVVVectorBitsMin, RVVVectorBitsMax);
-  return PowerOf2Floor(Max < 128 ? 0 : Max);
+  return PowerOf2Floor((Max < 128 || Max > 65536) ? 0 : Max);
 }
 
 unsigned RISCVSubtarget::getMinRVVVectorSizeInBits() const {
   assert(hasStdExtV() &&
          "Tried to get vector length without V extension support!");
   assert((RVVVectorBitsMin == 0 ||
-          (RVVVectorBitsMin >= 128 && isPowerOf2_32(RVVVectorBitsMin))) &&
-         "V extension requires vector length to be at least 128 and a power of "
-         "2!");
+          (RVVVectorBitsMin >= 128 && RVVVectorBitsMax <= 65536 &&
+           isPowerOf2_32(RVVVectorBitsMin))) &&
+         "V extension requires vector length to be in the range of 128 to "
+         "65536 and a power of 2!");
   assert((RVVVectorBitsMax >= RVVVectorBitsMin || RVVVectorBitsMax == 0) &&
          "Minimum V extension vector length should not be larger than its "
          "maximum!");
   unsigned Min = RVVVectorBitsMin;
   if (RVVVectorBitsMax != 0)
     Min = std::min(RVVVectorBitsMin, RVVVectorBitsMax);
-  return PowerOf2Floor(Min < 128 ? 0 : Min);
+  return PowerOf2Floor((Min < 128 || Min > 65536) ? 0 : Min);
 }
 
 unsigned RISCVSubtarget::getMaxLMULForFixedLengthVectors() const {
Index: llvm/lib/Target/RISCV/RISCVRegisterInfo.td
===================================================================
--- llvm/lib/Target/RISCV/RISCVRegisterInfo.td
+++ llvm/lib/Target/RISCV/RISCVRegisterInfo.td
@@ -285,8 +285,7 @@
 
 // Vector type mapping to LLVM types.
 //
-// Though the V extension allows that VLEN be as small as 8,
-// this approach assumes that VLEN>=64.
+// The V vector extension requires that VLEN >= 128 and <= 65536.
 // Additionally, the only supported ELEN values are 32 and 64,
 // thus `vscale` can be defined as VLEN/64,
 // allowing the same types with either ELEN value.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D106134.359254.patch
Type: text/x-patch
Size: 2765 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20210716/4ae14d8c/attachment.bin>