[PATCH] D129477: [InstCombine][SVE] Bail out of isSafeToLoadUnconditionally for scalable types

[Peter Waller via Phabricator via llvm-commits]

peterwaller-arm created this revision.
peterwaller-arm added reviewers: c-rhodes, paulwalker-arm, sdesmalen, david-arm.
Herald added subscribers: psnobl, hiraditya, tschuett.
Herald added a reviewer: efriedma.
Herald added a project: All.
peterwaller-arm requested review of this revision.
Herald added subscribers: llvm-commits, alextsao1999.
Herald added a project: LLVM.

`isSafeToLoadUnconditionally` currently assumes sized types. Bail out for now.
This fixes a TypeSize warning reachable from instcombine via (load (select
cond, ptr, ptr)).


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D129477

Files:
  llvm/lib/Analysis/Loads.cpp
  llvm/test/Transforms/InstCombine/scalable-select.ll


Index: llvm/test/Transforms/InstCombine/scalable-select.ll
===================================================================
--- llvm/test/Transforms/InstCombine/scalable-select.ll
+++ llvm/test/Transforms/InstCombine/scalable-select.ll
@@ -15,3 +15,17 @@
   %d = select <vscale x 1 x i1> %m, <vscale x 1 x i32> %c, <vscale x 1 x i32> %b
   ret <vscale x 1 x i32> %d
 }
+
+define <vscale x 2 x i64> @load_scalable_of_selected_ptrs(ptr %p0, ptr %p1, i64 %idx) {
+entry:
+  ; Test introduced in response to a TypeSize warning arising from isSafeToLoadUnconditionally via instcombine.
+  ; deref (p0[0] < p1[0] ? p0 : p1) as <vscale x 2 x i64>.
+  %arrayidx0 = getelementptr inbounds i32, ptr %p0, i64 %idx
+  %arrayidx1 = getelementptr inbounds i32, ptr %p1, i64 %idx
+  %l0 = load i32, ptr %arrayidx0
+  %l1 = load i32, ptr %arrayidx1
+  %cmp = icmp slt i32 %l0, %l1
+  %sel = select i1 %cmp, ptr %arrayidx0, ptr %arrayidx1
+  %ret = load <vscale x 2 x i64>, ptr %sel
+  ret <vscale x 2 x i64> %ret
+}
Index: llvm/lib/Analysis/Loads.cpp
===================================================================
--- llvm/lib/Analysis/Loads.cpp
+++ llvm/lib/Analysis/Loads.cpp
@@ -405,7 +405,10 @@
                                        Instruction *ScanFrom,
                                        const DominatorTree *DT,
                                        const TargetLibraryInfo *TLI) {
-  APInt Size(DL.getIndexTypeSizeInBits(V->getType()), DL.getTypeStoreSize(Ty));
+  TypeSize TySize = DL.getTypeStoreSize(Ty);
+  if (TySize.isScalable())
+    return false;
+  APInt Size(DL.getIndexTypeSizeInBits(V->getType()), TySize);
   return isSafeToLoadUnconditionally(V, Alignment, Size, DL, ScanFrom, DT, TLI);
 }
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D129477.443595.patch
Type: text/x-patch
Size: 1716 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20220711/e8e74067/attachment.bin>