[llvm] 7f90387 - DSE: fix builtin function recognition to take decl into account

[Nuno Lopes via llvm-commits]

Author: Nuno Lopes
Date: 2020-07-02T10:28:47+01:00
New Revision: 7f903873b8a937acec2e2cc232e70cba53061352

URL: https://github.com/llvm/llvm-project/commit/7f903873b8a937acec2e2cc232e70cba53061352
DIFF: https://github.com/llvm/llvm-project/commit/7f903873b8a937acec2e2cc232e70cba53061352.diff

LOG: DSE: fix builtin function recognition to take decl into account

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
    llvm/test/Transforms/DeadStoreElimination/MSSA/libcalls.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
index f55278d56790..7e172544595a 100644
--- a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
@@ -210,18 +210,16 @@ static bool hasAnalyzableMemoryWrite(Instruction *I,
     }
   }
   if (auto *CB = dyn_cast<CallBase>(I)) {
-    if (Function *F = CB->getCalledFunction()) {
-      LibFunc LF;
-      if (TLI.getLibFunc(*F, LF) && TLI.has(LF)) {
-        switch (LF) {
-        case LibFunc_strcpy:
-        case LibFunc_strncpy:
-        case LibFunc_strcat:
-        case LibFunc_strncat:
-          return true;
-        default:
-          return false;
-        }
+    LibFunc LF;
+    if (TLI.getLibFunc(*CB, LF) && TLI.has(LF)) {
+      switch (LF) {
+      case LibFunc_strcpy:
+      case LibFunc_strncpy:
+      case LibFunc_strcat:
+      case LibFunc_strncat:
+        return true;
+      default:
+        return false;
       }
     }
   }
@@ -1581,16 +1579,17 @@ struct DSEState {
       return {MemoryLocation::getForDest(MTI)};
 
     if (auto *CB = dyn_cast<CallBase>(I)) {
-      if (Function *F = CB->getCalledFunction()) {
-        StringRef FnName = F->getName();
-        if (TLI.has(LibFunc_strcpy) && FnName == TLI.getName(LibFunc_strcpy))
-          return {MemoryLocation(CB->getArgOperand(0))};
-        if (TLI.has(LibFunc_strncpy) && FnName == TLI.getName(LibFunc_strncpy))
-          return {MemoryLocation(CB->getArgOperand(0))};
-        if (TLI.has(LibFunc_strcat) && FnName == TLI.getName(LibFunc_strcat))
-          return {MemoryLocation(CB->getArgOperand(0))};
-        if (TLI.has(LibFunc_strncat) && FnName == TLI.getName(LibFunc_strncat))
+      LibFunc LF;
+      if (TLI.getLibFunc(*CB, LF) && TLI.has(LF)) {
+        switch (LF) {
+        case LibFunc_strcpy:
+        case LibFunc_strncpy:
+        case LibFunc_strcat:
+        case LibFunc_strncat:
           return {MemoryLocation(CB->getArgOperand(0))};
+        default:
+          break;
+        }
       }
       return None;
     }

diff  --git a/llvm/test/Transforms/DeadStoreElimination/MSSA/libcalls.ll b/llvm/test/Transforms/DeadStoreElimination/MSSA/libcalls.ll
index e13e3a193d00..94faca15c1b6 100644
--- a/llvm/test/Transforms/DeadStoreElimination/MSSA/libcalls.ll
+++ b/llvm/test/Transforms/DeadStoreElimination/MSSA/libcalls.ll
@@ -1,5 +1,7 @@
 ; RUN: opt -S -basic-aa -dse -enable-dse-memoryssa < %s | FileCheck %s
 
+target triple = "x86_64-unknown-linux-gnu"
+
 declare i8* @strcpy(i8* %dest, i8* %src) nounwind
 define void @test1(i8* %src) {
 ; CHECK-LABEL: @test1(
@@ -11,13 +13,13 @@ define void @test1(i8* %src) {
   ret void
 }
 
-declare i8* @strncpy(i8* %dest, i8* %src, i32 %n) nounwind
+declare i8* @strncpy(i8* %dest, i8* %src, i64 %n) nounwind
 define void @test2(i8* %src) {
 ; CHECK-LABEL: @test2(
   %B = alloca [16 x i8]
   %dest = getelementptr inbounds [16 x i8], [16 x i8]* %B, i64 0, i64 0
 ; CHECK-NOT: @strncpy
-  %call = call i8* @strncpy(i8* %dest, i8* %src, i32 12)
+  %call = call i8* @strncpy(i8* %dest, i8* %src, i64 12)
 ; CHECK: ret void
   ret void
 }
@@ -33,13 +35,13 @@ define void @test3(i8* %src) {
   ret void
 }
 
-declare i8* @strncat(i8* %dest, i8* %src, i32 %n) nounwind
+declare i8* @strncat(i8* %dest, i8* %src, i64 %n) nounwind
 define void @test4(i8* %src) {
 ; CHECK-LABEL: @test4(
   %B = alloca [16 x i8]
   %dest = getelementptr inbounds [16 x i8], [16 x i8]* %B, i64 0, i64 0
 ; CHECK-NOT: @strncat
-  %call = call i8* @strncat(i8* %dest, i8* %src, i32 12)
+  %call = call i8* @strncat(i8* %dest, i8* %src, i64 12)
 ; CHECK: ret void
   ret void
 }