From f58a9dac73b7b5f1bb8cad13b73285b2e1af66c9 Mon Sep 17 00:00:00 2001
From: Fangrui Song <maskray@google.com>
Date: Fri, 12 Jul 2019 02:01:51 +0000
Subject: [Driver] Refactor interaction between -f(no-)?omit-frame-pointer and
 -m(no-)?omit-leaf-frame-pointer

Use a tri-state enum to represent shouldUseFramePointer() and
shouldUseLeafFramePointer().

This simplifies the logic and fixes PR9825:
  -fno-omit-frame-pointer doesn't imply -mno-omit-leaf-frame-pointer.

and PR24003:
  /Oy- /O2 should not omit leaf frame pointer: this matches MSVC x86-32.
  (/Oy- is a no-op on MSVC x86-64.)

and:
  when CC1 option -mdisable-fp-elim if absent, -momit-leaf-frame-pointer
  can also be omitted.

The new behavior matches GCC:
  -fomit-frame-pointer wins over -mno-omit-leaf-frame-pointer
  -fno-omit-frame-pointer loses out to -momit-leaf-frame-pointer

The behavior makes lots of sense. We have 4 states:

- 00) leaf retained, non-leaf retained
- 01) leaf retained, non-leaf omitted  (this is invalid)
- 10) leaf omitted, non-leaf retained  (what -momit-leaf-frame-pointer was designed for)
- 11) leaf omitted, non-leaf omitted

"omit" options taking precedence over "no-omit" options is the only way
to make 3 valid states representable with -f(no-)?omit-frame-pointer and
-m(no-)?omit-leaf-pointer.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D64294

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@365860 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/Driver/frame-pointer-elim.c | 79 ++++++++++++++++++++++++++--------------
 1 file changed, 52 insertions(+), 27 deletions(-)

(limited to 'test/Driver/frame-pointer-elim.c')

diff --git a/test/Driver/frame-pointer-elim.c b/test/Driver/frame-pointer-elim.c
index 6fcd3eb75a..3e6df2aaf2 100644
--- a/test/Driver/frame-pointer-elim.c
+++ b/test/Driver/frame-pointer-elim.c
@@ -1,48 +1,74 @@
-// For these next two tests when optimized we should omit the leaf frame
-// pointer, for unoptimized we should have a leaf frame pointer.
-// RUN: %clang -### -target i386-pc-linux-gnu -S -O1 %s 2>&1 | \
-// RUN:   FileCheck --check-prefix=LINUX-OPT %s
-// LINUX-OPT: "-momit-leaf-frame-pointer"
+// KEEP-ALL: "-mdisable-fp-elim"
+// KEEP-ALL-NOT: "-momit-leaf-frame-pointer"
 
-// RUN: %clang -### -target i386-pc-linux-gnu -S %s 2>&1 | \
-// RUN:   FileCheck --check-prefix=LINUX %s
-// LINUX-NOT: "-momit-leaf-frame-pointer"
+// KEEP-NON-LEAF: "-mdisable-fp-elim"
+// KEEP-NON-LEAF: "-momit-leaf-frame-pointer"
+
+// KEEP-NONE-NOT: "-mdisable-fp-elim"
+// KEEP-NONE-NOT: "-momit-leaf-frame-pointer"
+
+// On Linux x86, omit frame pointer when optimization is enabled.
+// RUN: %clang -### -target i386-linux -S -fomit-frame-pointer %s 2>&1 | \
+// RUN:   FileCheck --check-prefix=KEEP-NONE %s
+// RUN: %clang -### -target i386-linux -S -O1 %s 2>&1 | \
+// RUN:   FileCheck --check-prefix=KEEP-NONE %s
+
+// -fno-omit-frame-pointer or -pg disables frame pointer omission.
+// RUN: %clang -### -target i386-linux -S %s 2>&1 | \
+// RUN:   FileCheck --check-prefix=KEEP-ALL %s
+// RUN: %clang -### -target i386-linux -S -O1 -fno-omit-frame-pointer %s 2>&1 | \
+// RUN:   FileCheck --check-prefix=KEEP-ALL %s
+// RUN: %clang -### -target i386-linux -S -O1 -pg %s 2>&1 | \
+// RUN:   FileCheck --check-prefix=KEEP-ALL %s
+
+// -momit-leaf-frame-pointer omits leaf frame pointer.
+// -fno-omit-frame-pointer loses out to -momit-leaf-frame-pointer.
+// RUN: %clang -### -target i386 -S -momit-leaf-frame-pointer %s 2>&1 | \
+// RUN:   FileCheck --check-prefix=KEEP-NON-LEAF %s
+// RUN: %clang -### -target i386-linux -S -O1 -fno-omit-frame-pointer -momit-leaf-frame-pointer %s 2>&1 | \
+// RUN:   FileCheck --check-prefix=KEEP-NON-LEAF %s
+// RUN: %clang -### -target i386-linux -S -O1 -momit-leaf-frame-pointer %s 2>&1 | \
+// RUN:   FileCheck --check-prefix=KEEP-NONE %s
+
+// Explicit or default -fomit-frame-pointer wins over -mno-omit-leaf-frame-pointer.
+// RUN: %clang -### -target i386 -S %s -fomit-frame-pointer -mno-omit-leaf-frame-pointer 2>&1 | \
+// RUN:   FileCheck --check-prefix=KEEP-NONE %s
+// RUN: %clang -### -target i386-linux -S %s -O1 -mno-omit-leaf-frame-pointer 2>&1 | \
+// RUN:   FileCheck --check-prefix=KEEP-NONE %s
+
+// -pg -fomit-frame-pointer => error.
+// RUN: %clang -### -S -fomit-frame-pointer -pg %s 2>&1 | FileCheck -check-prefix=CHECK-NO-MIX-OMIT-FP-PG %s
+// RUN: %clang -### -S -fomit-frame-pointer -fno-omit-frame-pointer -pg %s 2>&1 | FileCheck -check-prefix=CHECK-MIX-NO-OMIT-FP-PG %s
+// CHECK-NO-MIX-OMIT-FP-PG: '-fomit-frame-pointer' not allowed with '-pg'
+// CHECK-MIX-NO-OMIT-FP-PG-NOT: '-fomit-frame-pointer' not allowed with '-pg'
 
 // CloudABI follows the same rules as Linux.
 // RUN: %clang -### -target x86_64-unknown-cloudabi -S -O1 %s 2>&1 | \
-// RUN:   FileCheck --check-prefix=CLOUDABI-OPT %s
-// CLOUDABI-OPT: "-momit-leaf-frame-pointer"
+// RUN:   FileCheck --check-prefix=KEEP-NONE %s
 
 // RUN: %clang -### -target x86_64-unknown-cloudabi -S %s 2>&1 | \
-// RUN:   FileCheck --check-prefix=CLOUDABI %s
-// CLOUDABI-NOT: "-momit-leaf-frame-pointer"
+// RUN:   FileCheck --check-prefix=KEEP-ALL %s
 
 // NetBSD follows the same rules as Linux.
 // RUN: %clang -### -target x86_64-unknown-netbsd -S -O1 %s 2>&1 | \
-// RUN:   FileCheck --check-prefix=NETBSD-OPT %s
-// NETBSD-OPT: "-momit-leaf-frame-pointer"
+// RUN:   FileCheck --check-prefix=KEEP-NONE %s
 
 // RUN: %clang -### -target x86_64-unknown-netbsd -S %s 2>&1 | \
-// RUN:   FileCheck --check-prefix=NETBSD %s
-// NETBSD-NOT: "-momit-leaf-frame-pointer"
+// RUN:   FileCheck --check-prefix=KEEP-ALL %s
 
 // Darwin disables omitting the leaf frame pointer even under optimization
 // unless the command lines are given.
 // RUN: %clang -### -target i386-apple-darwin -S %s 2>&1 | \
-// RUN:   FileCheck --check-prefix=DARWIN %s
-// DARWIN: "-mdisable-fp-elim"
+// RUN:   FileCheck --check-prefix=KEEP-ALL %s
 
 // RUN: %clang -### -target i386-apple-darwin -S -O1 %s 2>&1 | \
-// RUN:   FileCheck --check-prefix=DARWIN-OPT %s
-// DARWIN-OPT-NOT: "-momit-leaf-frame-pointer"
+// RUN:   FileCheck --check-prefix=KEEP-ALL %s
 
 // RUN: %clang -### -target i386-darwin -S -fomit-frame-pointer %s 2>&1 | \
-// RUN:   FileCheck --check-prefix=OMIT_ALL %s
-// OMIT_ALL-NOT: "-mdisable-fp-elim"
+// RUN:   FileCheck --check-prefix=KEEP-NONE %s
 
 // RUN: %clang -### -target i386-darwin -S -momit-leaf-frame-pointer %s 2>&1 | \
-// RUN:   FileCheck --check-prefix=OMIT_LEAF %s
-// OMIT_LEAF: "-momit-leaf-frame-pointer"
+// RUN:   FileCheck --check-prefix=KEEP-NON-LEAF %s
 
 // RUN: %clang -### -target armv7s-apple-ios -fomit-frame-pointer %s 2>&1 | \
 // RUN:   FileCheck --check-prefix=WARN-OMIT-7S %s
@@ -63,11 +89,10 @@
 // WARN-OMIT-LEAF-7S: "-momit-leaf-frame-pointer"
 
 // On the PS4, we default to omitting the frame pointer on leaf functions
-// (OMIT_LEAF check line is above)
 // RUN: %clang -### -target x86_64-scei-ps4 -S %s 2>&1 | \
-// RUN:   FileCheck --check-prefix=OMIT_LEAF %s
+// RUN:   FileCheck --check-prefix=KEEP-NON-LEAF %s
 // RUN: %clang -### -target x86_64-scei-ps4 -S -O2 %s 2>&1 | \
-// RUN:   FileCheck --check-prefix=OMIT_LEAF %s
+// RUN:   FileCheck --check-prefix=KEEP-NON-LEAF %s
 
 void f0() {}
 void f1() { f0(); }
-- 
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