[PATCH] D70143: Check result of emitStrLen before passing it to CreateGEP

[Dimitry Andric via Phabricator via cfe-commits]

dim updated this revision to Diff 229172.
dim added a comment.

Now `opt` supports `-disable-builtin`, move the test to `llvm/test/Transforms/InstCombine`.

Also use code style of nearest preceding constructs.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D70143/new/

https://reviews.llvm.org/D70143

Files:
  llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
  llvm/test/Transforms/InstCombine/pr43081.ll


Index: llvm/test/Transforms/InstCombine/pr43081.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/InstCombine/pr43081.ll
@@ -0,0 +1,15 @@
+; RUN: opt < %s -instcombine -disable-builtin strlen -S | FileCheck %s
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+
+declare i8* @strchr(i8*, i32)
+
+define i8* @pr43081(i8* %a) {
+entry:
+  %a.addr = alloca i8*, align 8
+  store i8* %a, i8** %a.addr, align 8
+  %0 = load i8*, i8** %a.addr, align 8
+  %call = call i8* @strchr(i8* %0, i32 0)
+  ret i8* %call
+; CHECK: call i8* @strchr
+}
Index: llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
===================================================================
--- llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -364,8 +364,8 @@
   StringRef Str;
   if (!getConstantStringInfo(SrcStr, Str)) {
     if (CharC->isZero()) // strchr(p, 0) -> p + strlen(p)
-      return B.CreateGEP(B.getInt8Ty(), SrcStr, emitStrLen(SrcStr, B, DL, TLI),
-                         "strchr");
+      if (Value *StrLen = emitStrLen(SrcStr, B, DL, TLI))
+        return B.CreateGEP(B.getInt8Ty(), SrcStr, StrLen, "strchr");
     return nullptr;
   }
 


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