From 3fec6ee9cb6d107d26e6b133b985cd4957beb806 Mon Sep 17 00:00:00 2001 From: Davide Italiano Date: Sat, 4 Feb 2017 19:44:14 +0000 Subject: [PATCH] [IPCP] Don't propagate return value for naked functions. This is pretty much the same change made in SCCP. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294098 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/IPO/IPConstantPropagation.cpp | 8 +++++++- test/Transforms/IPConstantProp/naked-return.ll | 1 + 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/lib/Transforms/IPO/IPConstantPropagation.cpp b/lib/Transforms/IPO/IPConstantPropagation.cpp index 916135e33cd..349807496dc 100644 --- a/lib/Transforms/IPO/IPConstantPropagation.cpp +++ b/lib/Transforms/IPO/IPConstantPropagation.cpp @@ -136,7 +136,13 @@ static bool PropagateConstantReturn(Function &F) { // For more details, see GlobalValue::mayBeDerefined. if (!F.isDefinitionExact()) return false; - + + // Don't touch naked functions. The may contain asm returning + // value we don't see, so we may end up interprocedurally propagating + // the return value incorrectly. + if (F.hasFnAttribute(Attribute::Naked)) + return false; + // Check to see if this function returns a constant. SmallVector RetVals; StructType *STy = dyn_cast(F.getReturnType()); diff --git a/test/Transforms/IPConstantProp/naked-return.ll b/test/Transforms/IPConstantProp/naked-return.ll index ef4747175e0..3a2dedafcd3 100644 --- a/test/Transforms/IPConstantProp/naked-return.ll +++ b/test/Transforms/IPConstantProp/naked-return.ll @@ -1,4 +1,5 @@ ; RUN: opt -ipsccp -S %s | FileCheck %s +; RUN: opt -ipconstprop -S %s | FileCheck %s target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32" target triple = "i686-pc-windows-msvc19.0.24215" -- 2.50.1