diff --git a/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp b/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp index 75fb2d40653f..493d014586c6 100644 --- a/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp +++ b/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp @@ -872,6 +872,10 @@ bool MemOPSizeOpt::perform(MemIntrinsic *MI) { if (ActualCount < MemOPCountThreshold) return false; + // Skip if the total value profiled count is 0, in which case we can't + // scale up the counts properly (and there is no profitable transformation). + if (TotalCount == 0) + return false; TotalCount = ActualCount; if (MemOPScaleCount) diff --git a/llvm/test/Transforms/PGOProfile/memop_size_opt_zero.ll b/llvm/test/Transforms/PGOProfile/memop_size_opt_zero.ll new file mode 100644 index 000000000000..ede34f0de803 --- /dev/null +++ b/llvm/test/Transforms/PGOProfile/memop_size_opt_zero.ll @@ -0,0 +1,19 @@ +; Test to ensure the pgo memop optimization pass doesn't try to scale +; up a value profile with a 0 count, which would lead to divide by 0. +; RUN: opt < %s -passes=pgo-memop-opt -pgo-memop-count-threshold=1 -S | FileCheck %s --check-prefix=MEMOP_OPT +; RUN: opt < %s -pgo-memop-opt -pgo-memop-count-threshold=1 -S | FileCheck %s --check-prefix=MEMOP_OPT + +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +define void @foo(i8* %dst, i8* %src, i64 %conv) !prof !0 { + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %conv, i32 1, i1 false), !prof !1 + ret void +} + +; MEMOP_OPT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %conv, i32 1, i1 false), !prof !1 + +!0 = !{!"function_entry_count", i64 1} +!1 = !{!"VP", i32 1, i64 0, i64 1, i64 0, i64 2, i64 0, i64 3, i64 0, i64 9, i64 0, i64 4, i64 0, i64 5, i64 0, i64 6, i64 0, i64 7, i64 0, i64 8, i64 0} + +declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture writeonly, i8* nocapture readonly, i64, i32, i1)