From 6c1e6bbe0c609489ef49f9d64f1370a43e05c19c Mon Sep 17 00:00:00 2001
From: Luke Cheeseman <luke.cheeseman@arm.com>
Date: Thu, 22 Feb 2018 14:42:08 +0000
Subject: [FunctionAttrs][ArgumentPromotion][GlobalOpt] Disable some
 optimisations passes for naked functions

- Fix for bug 36078.
- Prevent the functionattrs, function-attrs, globalopt and argpromotion passes
  from changing naked functions.
- These passes can perform some alterations to the functions that should not be
  applied. An example is removing parameters that are seemingly not used because
  they are only referenced in the inline assembly. Another example is marking
  the function as fastcc.

llvm-svn: 325788
---
 .../ArgumentPromotion/naked_functions.ll           | 23 ++++++++++++++++++++
 .../Transforms/FunctionAttrs/naked_functions.ll    | 25 ++++++++++++++++++++++
 llvm/test/Transforms/GlobalOpt/naked_functions.ll  | 23 ++++++++++++++++++++
 3 files changed, 71 insertions(+)
 create mode 100644 llvm/test/Transforms/ArgumentPromotion/naked_functions.ll
 create mode 100644 llvm/test/Transforms/FunctionAttrs/naked_functions.ll
 create mode 100644 llvm/test/Transforms/GlobalOpt/naked_functions.ll

(limited to 'llvm/test/Transforms')

diff --git a/llvm/test/Transforms/ArgumentPromotion/naked_functions.ll b/llvm/test/Transforms/ArgumentPromotion/naked_functions.ll
new file mode 100644
index 00000000000..70a63f4d02e
--- /dev/null
+++ b/llvm/test/Transforms/ArgumentPromotion/naked_functions.ll
@@ -0,0 +1,23 @@
+; RUN: opt < %s -argpromotion -S | FileCheck %s
+
+; Don't promote paramaters of/arguments to naked functions
+
+@g = common global i32 0, align 4
+
+define i32 @bar() {
+entry:
+  %call = call i32 @foo(i32* @g)
+; CHECK: %call = call i32 @foo(i32* @g)
+  ret i32 %call
+}
+
+define internal i32 @foo(i32*) #0 {
+entry:
+  %retval = alloca i32, align 4
+  call void asm sideeffect "ldr r0, [r0] \0Abx lr        \0A", ""()
+  unreachable
+}
+
+; CHECK: define internal i32 @foo(i32*)
+
+attributes #0 = { naked }
diff --git a/llvm/test/Transforms/FunctionAttrs/naked_functions.ll b/llvm/test/Transforms/FunctionAttrs/naked_functions.ll
new file mode 100644
index 00000000000..d34dc0c20d9
--- /dev/null
+++ b/llvm/test/Transforms/FunctionAttrs/naked_functions.ll
@@ -0,0 +1,25 @@
+; RUN: opt -S -functionattrs %s | FileCheck %s
+; RUN: opt -S -passes='function-attrs' %s | FileCheck %s
+
+; Don't change the attributes of parameters of naked functions, in particular
+; don't mark them as readnone
+
+@g = common global i32 0, align 4
+
+define i32 @bar() {
+entry:
+  %call = call i32 @foo(i32* @g)
+; CHECK: %call = call i32 @foo(i32* @g)
+  ret i32 %call
+}
+
+define internal i32 @foo(i32*) #0 {
+entry:
+  %retval = alloca i32, align 4
+  call void asm sideeffect "ldr r0, [r0] \0Abx lr        \0A", ""()
+  unreachable
+}
+
+; CHECK: define internal i32 @foo(i32*)
+
+attributes #0 = { naked }
diff --git a/llvm/test/Transforms/GlobalOpt/naked_functions.ll b/llvm/test/Transforms/GlobalOpt/naked_functions.ll
new file mode 100644
index 00000000000..80c3aa8c3b2
--- /dev/null
+++ b/llvm/test/Transforms/GlobalOpt/naked_functions.ll
@@ -0,0 +1,23 @@
+; RUN: opt < %s -globalopt -S | FileCheck %s
+
+; Check that naked functions don't get marked with fast calling conventions
+
+@g = common global i32 0, align 4
+
+define i32 @bar() {
+entry:
+  %call = call i32 @foo(i32* @g)
+; CHECK: %call = call i32 @foo(i32* @g)
+  ret i32 %call
+}
+
+define internal i32 @foo(i32*) #0 {
+entry:
+  %retval = alloca i32, align 4
+  call void asm sideeffect "ldr r0, [r0] \0Abx lr        \0A", ""()
+  unreachable
+}
+
+; CHECK: define internal i32 @foo(i32*)
+
+attributes #0 = { naked }
-- 
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