[InstSimplify][CaptureTracking] Reduce scope of special case

As described in PR54002, the "icmp of load from global" special
case in CaptureTracking is incorrect, as is the InstSimplify code
that makes use of it.

This moves the special case from CaptureTracking into InstSimplify
to limit its scope to the buggy transform only, and not affect
other code using CaptureTracking as well.

1 files changed, 1 insertions, 6 deletions

diff --git a/llvm/lib/Analysis/CaptureTracking.cpp b/llvm/lib/Analysis/CaptureTracking.cpp
index 7f3a2b49aca9..34a320435c0a 100644
--- a/llvm/lib/Analysis/CaptureTracking.cpp
+++ b/llvm/lib/Analysis/CaptureTracking.cpp
@@ -403,12 +403,7 @@ UseCaptureKind llvm::DetermineUseCaptureKind(
           return UseCaptureKind::NO_CAPTURE;
       }
     }
-    // Comparison against value stored in global variable. Given the pointer
-    // does not escape, its value cannot be guessed and stored separately in a
-    // global variable.
-    auto *LI = dyn_cast<LoadInst>(I->getOperand(OtherIdx));
-    if (LI && isa<GlobalVariable>(LI->getPointerOperand()))
-      return UseCaptureKind::NO_CAPTURE;
+
     // Otherwise, be conservative. There are crazy ways to capture pointers
     // using comparisons.
     return UseCaptureKind::MAY_CAPTURE;