Revert "[IR][ARM] Add function pointer alignment to datalayout"

This reverts commit 2391bfca97290181ae65796ea6da135d1b6d037b.

This reverts rL355522 (https://reviews.llvm.org/D57335).

Kills buildbots that use '-Werror' with the following error:
	/var/lib/buildbot/sanitizer-buildbot6/sanitizer-x86_64-linux-android/build/llvm/lib/IR/Value.cpp:657:7: error: default label in switch which covers all enumeration values [-Werror,-Wcovered-switch-default]

See buildbots http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/30200/steps/check-llvm%20asan/logs/stdio for more information.

llvm-svn: 355537

1 files changed, 4 insertions, 24 deletions

diff --git a/llvm/lib/IR/ConstantFold.cpp b/llvm/lib/IR/ConstantFold.cpp
index 3784405ecb0..037f120f47d 100644
--- a/llvm/lib/IR/ConstantFold.cpp
+++ b/llvm/lib/IR/ConstantFold.cpp
@@ -26,7 +26,6 @@
 #include "llvm/IR/GlobalAlias.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/Instructions.h"
-#include "llvm/IR/Module.h"
 #include "llvm/IR/Operator.h"
 #include "llvm/IR/PatternMatch.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -1077,29 +1076,10 @@ Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode, Constant *C1,
             isa<GlobalValue>(CE1->getOperand(0))) {
           GlobalValue *GV = cast<GlobalValue>(CE1->getOperand(0));
 
-          unsigned GVAlign;
-
-          if (Module *TheModule = GV->getParent()) {
-            GVAlign = GV->getPointerAlignment(TheModule->getDataLayout());
-
-            // If the function alignment is not specified then assume that it
-            // is 4.
-            // This is dangerous; on x86, the alignment of the pointer
-            // corresponds to the alignment of the function, but might be less
-            // than 4 if it isn't explicitly specified.
-            // However, a fix for this behaviour was reverted because it
-            // increased code size (see https://reviews.llvm.org/D55115)
-            // FIXME: This code should be deleted once existing targets have
-            // appropriate defaults
-            if (GVAlign == 0U && isa<Function>(GV))
-              GVAlign = 4U;
-          } else if (isa<Function>(GV)) {
-            // Without a datalayout we have to assume the worst case: that the
-            // function pointer isn't aligned at all.
-            GVAlign = 0U;
-          } else {
-            GVAlign = GV->getAlignment();
-          }
+          // Functions are at least 4-byte aligned.
+          unsigned GVAlign = GV->getAlignment();
+          if (isa<Function>(GV))
+            GVAlign = std::max(GVAlign, 4U);
 
           if (GVAlign > 1) {
             unsigned DstWidth = CI2->getType()->getBitWidth();