[PATCH] D127680: [BasicTTI] Allow generic handling of scalable vector fshr/fshl

[Philip Reames via Phabricator via llvm-commits]

reames created this revision.
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This change removes an explicit scalable vector bailout for fshl and fshr.  This bailout was added in 60e4698b9aba8 <https://reviews.llvm.org/rG60e4698b9aba8d9a2b27ac8a636c95ad1f7d94e0>, when sinking a unconditional bailout for all intrinsics into selected cases.  Its not clear if the bailout was originally unneeded, or if our cost model infrastructure has simply matured in the meantime.  Either way, the generic code appears to handle scalable vectors without issue.

Note that the RISC-V cost model changes here aren't particularly interesting.  They do probably better match the current lowering, but the main point is to have coverage of the BasicTTI path and simply show lack of crashing.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D127680

Files:
  llvm/include/llvm/CodeGen/BasicTTIImpl.h
  llvm/test/Analysis/CostModel/RISCV/rvv-intrinsics.ll


Index: llvm/test/Analysis/CostModel/RISCV/rvv-intrinsics.ll
===================================================================
--- llvm/test/Analysis/CostModel/RISCV/rvv-intrinsics.ll
+++ llvm/test/Analysis/CostModel/RISCV/rvv-intrinsics.ll
@@ -33,7 +33,7 @@
 
 define void @fshr(<vscale x 1 x i32> %a, <vscale x 1 x i32> %b, <vscale x 1 x i32> %c) {
 ; CHECK-LABEL: 'fshr'
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %1 = call <vscale x 1 x i32> @llvm.fshr.nxv1i32(<vscale x 1 x i32> %a, <vscale x 1 x i32> %b, <vscale x 1 x i32> %c)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 7 for instruction: %1 = call <vscale x 1 x i32> @llvm.fshr.nxv1i32(<vscale x 1 x i32> %a, <vscale x 1 x i32> %b, <vscale x 1 x i32> %c)
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret void
 ;
   call <vscale x 1 x i32> @llvm.fshr.v4i32(<vscale x 1 x i32> %a, <vscale x 1 x i32> %b, <vscale x 1 x i32> %c)
@@ -42,7 +42,7 @@
 
 define void @fshl(<vscale x 1 x i32> %a, <vscale x 1 x i32> %b, <vscale x 1 x i32> %c) {
 ; CHECK-LABEL: 'fshl'
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %1 = call <vscale x 1 x i32> @llvm.fshl.nxv1i32(<vscale x 1 x i32> %a, <vscale x 1 x i32> %b, <vscale x 1 x i32> %c)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 7 for instruction: %1 = call <vscale x 1 x i32> @llvm.fshl.nxv1i32(<vscale x 1 x i32> %a, <vscale x 1 x i32> %b, <vscale x 1 x i32> %c)
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret void
 ;
   call <vscale x 1 x i32> @llvm.fshl.v4i32(<vscale x 1 x i32> %a, <vscale x 1 x i32> %b, <vscale x 1 x i32> %c)
Index: llvm/include/llvm/CodeGen/BasicTTIImpl.h
===================================================================
--- llvm/include/llvm/CodeGen/BasicTTIImpl.h
+++ llvm/include/llvm/CodeGen/BasicTTIImpl.h
@@ -1500,8 +1500,6 @@
     }
     case Intrinsic::fshl:
     case Intrinsic::fshr: {
-      if (isa<ScalableVectorType>(RetTy))
-        return BaseT::getIntrinsicInstrCost(ICA, CostKind);
       const Value *X = Args[0];
       const Value *Y = Args[1];
       const Value *Z = Args[2];


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