https://github.com/markoshorro created https://github.com/llvm/llvm-project/pull/71072
The same idea as in 34d380e1f63a7e2cdb9ab1e6498f727fcd710a14, but for truncation instructions. Improvement for #59633. >From 0c5299adb30888aa0dfd7c3106547a69606d5ab1 Mon Sep 17 00:00:00 2001 From: Marcos Horro <marc...@amd.com> Date: Thu, 2 Nov 2023 15:35:07 +0000 Subject: [PATCH] [IndVars] Truncation also considered as bitcast optimization --- llvm/lib/Transforms/Utils/SimplifyIndVar.cpp | 5 ++-- .../Transforms/IndVarSimplify/casted-trunc.ll | 28 +++++++++++++++++++ 2 files changed, 31 insertions(+), 2 deletions(-) create mode 100644 llvm/test/Transforms/IndVarSimplify/casted-trunc.ll diff --git a/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp b/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp index a23ac41acaa58aa..740f726cb06b148 100644 --- a/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp @@ -908,8 +908,9 @@ void SimplifyIndvar::simplifyUsers(PHINode *CurrIV, IVVisitor *V) { if (replaceIVUserWithLoopInvariant(UseInst)) continue; - // Go further for the bitcast ''prtoint ptr to i64' - if (isa<PtrToIntInst>(UseInst)) + // Go further for the bitcast 'prtoint ptr to i64' or if the cast is done + // by truncation + if ((isa<PtrToIntInst>(UseInst)) || (isa<TruncInst>(UseInst))) for (Use &U : UseInst->uses()) { Instruction *User = cast<Instruction>(U.getUser()); if (replaceIVUserWithLoopInvariant(User)) diff --git a/llvm/test/Transforms/IndVarSimplify/casted-trunc.ll b/llvm/test/Transforms/IndVarSimplify/casted-trunc.ll new file mode 100644 index 000000000000000..ef9db0b5774dada --- /dev/null +++ b/llvm/test/Transforms/IndVarSimplify/casted-trunc.ll @@ -0,0 +1,28 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt < %s -passes=indvars -S | FileCheck %s + +declare void @foo(i16 noundef) + +; Function Attrs: mustprogress noreturn uwtable +define void @bar(i64 noundef %ptr) { +; CHECK-LABEL: @bar( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[TMP0:%.*]] = trunc i64 [[PTR:%.*]] to i4 +; CHECK-NEXT: [[TMP1:%.*]] = zext i4 [[TMP0]] to i16 +; CHECK-NEXT: br label [[WHILE_BODY:%.*]] +; CHECK: while.body: +; CHECK-NEXT: tail call void @foo(i16 noundef signext [[TMP1]]) +; CHECK-NEXT: br label [[WHILE_BODY]] +; +entry: + br label %while.body + +while.body: ; preds = %entry, %while.body + %0 = phi i64 [ %ptr, %entry ], [ %add.ptr, %while.body ] + %1 = trunc i64 %0 to i16 + %and = and i16 %1, 15 ; loop invariant + tail call void @foo(i16 noundef signext %and) + %add.ptr = add nsw i64 %0, 16 + br label %while.body +} + _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits