ARM & AArch64: make use of common cmpxchg idioms after expansion

The C and C++ semantics for compare_exchange require it to return a bool
indicating success. This gets mapped to LLVM IR which follows each cmpxchg with
an icmp of the value loaded against the desired value.

When lowered to ldxr/stxr loops, this extra comparison is redundant: its
results are implicit in the control-flow of the function.

This commit makes two changes: it replaces that icmp with appropriate PHI
nodes, and then makes sure earlyCSE is called after expansion to actually make
use of the opportunities revealed.

I've also added -{arm,aarch64}-enable-atomic-tidy options, so that
existing fragile tests aren't perturbed too much by the change. Many
of them either rely on undef/unreachable too pervasively to be
restored to something well-defined (particularly while making sure
they test the same obscure assert from many years ago), or depend on a
particular CFG shape, which is disrupted by SimplifyCFG.

rdar://problem/16227836

llvm-svn: 209883

17 files changed, 25 insertions, 25 deletions

diff --git a/llvm/test/CodeGen/Thumb2/2009-08-01-WrongLDRBOpc.ll b/llvm/test/CodeGen/Thumb2/2009-08-01-WrongLDRBOpc.ll
index e0144531454..09e0ed1ead6 100644
--- a/llvm/test/CodeGen/Thumb2/2009-08-01-WrongLDRBOpc.ll
+++ b/llvm/test/CodeGen/Thumb2/2009-08-01-WrongLDRBOpc.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin9 -mcpu=cortex-a8 -relocation-model=pic -disable-fp-elim | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin9 -mcpu=cortex-a8 -relocation-model=pic -disable-fp-elim -arm-atomic-cfg-tidy=0 | FileCheck %s
 
 @csize = external global [100 x [20 x [4 x i8]]]		; <[100 x [20 x [4 x i8]]]*> [#uses=1]
 @vsize = external global [100 x [20 x [4 x i8]]]		; <[100 x [20 x [4 x i8]]]*> [#uses=1]
diff --git a/llvm/test/CodeGen/Thumb2/2009-08-06-SpDecBug.ll b/llvm/test/CodeGen/Thumb2/2009-08-06-SpDecBug.ll
index 940cfd15e08..c8eac8d4d09 100644
--- a/llvm/test/CodeGen/Thumb2/2009-08-06-SpDecBug.ll
+++ b/llvm/test/CodeGen/Thumb2/2009-08-06-SpDecBug.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-none-linux-gnueabi | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-none-linux-gnueabi -arm-atomic-cfg-tidy=0 | FileCheck %s
 ; PR4659
 ; PR4682
 
diff --git a/llvm/test/CodeGen/Thumb2/2009-09-28-ITBlockBug.ll b/llvm/test/CodeGen/Thumb2/2009-09-28-ITBlockBug.ll
index 52066d3f86a..a9a2478e403 100644
--- a/llvm/test/CodeGen/Thumb2/2009-09-28-ITBlockBug.ll
+++ b/llvm/test/CodeGen/Thumb2/2009-09-28-ITBlockBug.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a8 -disable-cgp-branch-opts | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a8 -disable-cgp-branch-opts -arm-atomic-cfg-tidy=0 | FileCheck %s
 
 %struct.pix_pos = type { i32, i32, i32, i32, i32, i32 }
 
diff --git a/llvm/test/CodeGen/Thumb2/2010-04-15-DynAllocBug.ll b/llvm/test/CodeGen/Thumb2/2010-04-15-DynAllocBug.ll
index 1b8bdb1c19b..8beb5b1c894 100644
--- a/llvm/test/CodeGen/Thumb2/2010-04-15-DynAllocBug.ll
+++ b/llvm/test/CodeGen/Thumb2/2010-04-15-DynAllocBug.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a8 -O3 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a8 -arm-atomic-cfg-tidy=0 -O3 | FileCheck %s
 ; rdar://7493908
 
 ; Make sure the result of the first dynamic_alloc isn't copied back to sp more
diff --git a/llvm/test/CodeGen/Thumb2/2010-06-21-TailMergeBug.ll b/llvm/test/CodeGen/Thumb2/2010-06-21-TailMergeBug.ll
index 810bfb79020..f3046e1fcb8 100644
--- a/llvm/test/CodeGen/Thumb2/2010-06-21-TailMergeBug.ll
+++ b/llvm/test/CodeGen/Thumb2/2010-06-21-TailMergeBug.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin -O3 -relocation-model=pic | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -O3 -relocation-model=pic -arm-atomic-cfg-tidy=0 | FileCheck %s
 ; rdar://8115404
 ; Tail merging must not split an IT block.
 
diff --git a/llvm/test/CodeGen/Thumb2/2010-11-22-EpilogueBug.ll b/llvm/test/CodeGen/Thumb2/2010-11-22-EpilogueBug.ll
index 75f5439b98c..3d89390d04c 100644
--- a/llvm/test/CodeGen/Thumb2/2010-11-22-EpilogueBug.ll
+++ b/llvm/test/CodeGen/Thumb2/2010-11-22-EpilogueBug.ll
@@ -1,5 +1,5 @@
 ; rdar://8465407
-; RUN: llc < %s -mtriple=thumbv7-apple-ios | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-ios -arm-atomic-cfg-tidy=0 | FileCheck %s
 
 %struct.buf = type opaque
 
diff --git a/llvm/test/CodeGen/Thumb2/2011-06-07-TwoAddrEarlyClobber.ll b/llvm/test/CodeGen/Thumb2/2011-06-07-TwoAddrEarlyClobber.ll
index b1ce3bb935e..240df83252c 100644
--- a/llvm/test/CodeGen/Thumb2/2011-06-07-TwoAddrEarlyClobber.ll
+++ b/llvm/test/CodeGen/Thumb2/2011-06-07-TwoAddrEarlyClobber.ll
@@ -1,4 +1,4 @@
-; RUN: llc -mtriple=thumbv7-apple-darwin10 < %s | FileCheck %s
+; RUN: llc -mtriple=thumbv7-apple-darwin10 -arm-atomic-cfg-tidy=0 < %s | FileCheck %s
 
 %struct.op = type { %struct.op*, %struct.op*, %struct.op* ()*, i32, i16, i16, i8, i8 }
 
diff --git a/llvm/test/CodeGen/Thumb2/buildvector-crash.ll b/llvm/test/CodeGen/Thumb2/buildvector-crash.ll
index 8a3c895bbe5..16e2298522f 100644
--- a/llvm/test/CodeGen/Thumb2/buildvector-crash.ll
+++ b/llvm/test/CodeGen/Thumb2/buildvector-crash.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -O3 -mtriple=thumbv7-apple-ios -mcpu=cortex-a8 | FileCheck %s
+; RUN: llc < %s -O3 -mtriple=thumbv7-apple-ios -arm-atomic-cfg-tidy=0 -mcpu=cortex-a8 | FileCheck %s
 ; Formerly crashed, 3573915.
 
 define void @RotateStarsFP_Vec() nounwind {
diff --git a/llvm/test/CodeGen/Thumb2/cross-rc-coalescing-2.ll b/llvm/test/CodeGen/Thumb2/cross-rc-coalescing-2.ll
index a9f948cf717..88c7f0f17ab 100644
--- a/llvm/test/CodeGen/Thumb2/cross-rc-coalescing-2.ll
+++ b/llvm/test/CodeGen/Thumb2/cross-rc-coalescing-2.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin9 -mcpu=cortex-a8 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin9 -mcpu=cortex-a8 -arm-atomic-cfg-tidy=0 | FileCheck %s
 
 define void @fht(float* nocapture %fz, i16 signext %n) nounwind {
 ; CHECK-LABEL: fht:
diff --git a/llvm/test/CodeGen/Thumb2/ldr-str-imm12.ll b/llvm/test/CodeGen/Thumb2/ldr-str-imm12.ll
index 36544d16d6f..d20eef0c8bb 100644
--- a/llvm/test/CodeGen/Thumb2/ldr-str-imm12.ll
+++ b/llvm/test/CodeGen/Thumb2/ldr-str-imm12.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a8 -relocation-model=pic -disable-fp-elim | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -arm-atomic-cfg-tidy=0 -mcpu=cortex-a8 -relocation-model=pic -disable-fp-elim | FileCheck %s
 ; rdar://7352504
 ; Make sure we use "str r9, [sp, #+28]" instead of "sub.w r4, r7, #256" followed by "str r9, [r4, #-32]".
 
diff --git a/llvm/test/CodeGen/Thumb2/thumb2-branch.ll b/llvm/test/CodeGen/Thumb2/thumb2-branch.ll
index a00b22d8502..332ed50ede6 100644
--- a/llvm/test/CodeGen/Thumb2/thumb2-branch.ll
+++ b/llvm/test/CodeGen/Thumb2/thumb2-branch.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mattr=+thumb2 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mattr=+thumb2 -arm-atomic-cfg-tidy=0 | FileCheck %s
 ; If-conversion defeats the purpose of this test, which is to check
 ; conditional branch generation, so a call to make sure it doesn't
 ; happen and we get actual branches.
diff --git a/llvm/test/CodeGen/Thumb2/thumb2-cbnz.ll b/llvm/test/CodeGen/Thumb2/thumb2-cbnz.ll
index 893bd0fdaef..f0f79168c90 100644
--- a/llvm/test/CodeGen/Thumb2/thumb2-cbnz.ll
+++ b/llvm/test/CodeGen/Thumb2/thumb2-cbnz.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a8 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a8 -arm-atomic-cfg-tidy=0 | FileCheck %s
 ; rdar://7354379
 
 declare double @foo(double) nounwind readnone
diff --git a/llvm/test/CodeGen/Thumb2/thumb2-ifcvt2.ll b/llvm/test/CodeGen/Thumb2/thumb2-ifcvt2.ll
index 403cd48035b..a861912fe11 100644
--- a/llvm/test/CodeGen/Thumb2/thumb2-ifcvt2.ll
+++ b/llvm/test/CodeGen/Thumb2/thumb2-ifcvt2.ll
@@ -1,6 +1,6 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-ios | FileCheck %s
-; RUN: llc < %s -mtriple=thumbv7-apple-ios -arm-default-it | FileCheck %s
-; RUN: llc < %s -mtriple=thumbv8-apple-ios -arm-no-restrict-it | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-ios -arm-atomic-cfg-tidy=0 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-ios -arm-atomic-cfg-tidy=0 -arm-default-it | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv8-apple-ios -arm-atomic-cfg-tidy=0 -arm-no-restrict-it | FileCheck %s
 
 define void @foo(i32 %X, i32 %Y) {
 entry:
diff --git a/llvm/test/CodeGen/Thumb2/thumb2-ifcvt3.ll b/llvm/test/CodeGen/Thumb2/thumb2-ifcvt3.ll
index a71aa3fb613..79667d43b95 100644
--- a/llvm/test/CodeGen/Thumb2/thumb2-ifcvt3.ll
+++ b/llvm/test/CodeGen/Thumb2/thumb2-ifcvt3.ll
@@ -1,6 +1,6 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin | FileCheck %s
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin -arm-default-it | FileCheck %s
-; RUN: llc < %s -mtriple=thumbv8-apple-darwin -arm-no-restrict-it | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -arm-atomic-cfg-tidy=0 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -arm-atomic-cfg-tidy=0 -arm-default-it | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv8-apple-darwin -arm-atomic-cfg-tidy=0 -arm-no-restrict-it | FileCheck %s
 
 ; There shouldn't be a unconditional branch at end of bb52.
 ; rdar://7184787
diff --git a/llvm/test/CodeGen/Thumb2/thumb2-spill-q.ll b/llvm/test/CodeGen/Thumb2/thumb2-spill-q.ll
index 52c10634491..94f472593b3 100644
--- a/llvm/test/CodeGen/Thumb2/thumb2-spill-q.ll
+++ b/llvm/test/CodeGen/Thumb2/thumb2-spill-q.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-elf -mattr=+neon | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-elf -mattr=+neon -arm-atomic-cfg-tidy=0 | FileCheck %s
 ; PR4789
 
 %bar = type { float, float, float }
diff --git a/llvm/test/CodeGen/Thumb2/v8_IT_3.ll b/llvm/test/CodeGen/Thumb2/v8_IT_3.ll
index 4dca24629b0..a028deebc8e 100644
--- a/llvm/test/CodeGen/Thumb2/v8_IT_3.ll
+++ b/llvm/test/CodeGen/Thumb2/v8_IT_3.ll
@@ -1,7 +1,7 @@
-; RUN: llc < %s -mtriple=thumbv8 | FileCheck %s
-; RUN: llc < %s -mtriple=thumbv7 -arm-restrict-it | FileCheck %s
-; RUN: llc < %s -mtriple=thumbv8 -relocation-model=pic | FileCheck %s --check-prefix=CHECK-PIC
-; RUN: llc < %s -mtriple=thumbv7 -arm-restrict-it -relocation-model=pic | FileCheck %s --check-prefix=CHECK-PIC
+; RUN: llc < %s -mtriple=thumbv8 -arm-atomic-cfg-tidy=0 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7 -arm-atomic-cfg-tidy=0 -arm-restrict-it | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv8 -arm-atomic-cfg-tidy=0 -relocation-model=pic | FileCheck %s --check-prefix=CHECK-PIC
+; RUN: llc < %s -mtriple=thumbv7 -arm-atomic-cfg-tidy=0 -arm-restrict-it -relocation-model=pic | FileCheck %s --check-prefix=CHECK-PIC
 
 %struct.FF = type { i32 (i32*)*, i32 (i32*, i32*, i32, i32, i32, i32)*, i32 (i32, i32, i8*)*, void ()*, i32 (i32, i8*, i32*)*, i32 ()* }
 %struct.BD = type { %struct.BD*, i32, i32, i32, i32, i64, i32 (%struct.BD*, i8*, i64, i32)*, i32 (%struct.BD*, i8*, i32, i32)*, i32 (%struct.BD*, i8*, i64, i32)*, i32 (%struct.BD*, i8*, i32, i32)*, i32 (%struct.BD*, i64, i32)*, [16 x i8], i64, i64 }
diff --git a/llvm/test/CodeGen/Thumb2/v8_IT_5.ll b/llvm/test/CodeGen/Thumb2/v8_IT_5.ll
index 2f352d6d5f1..2da75ad2143 100644
--- a/llvm/test/CodeGen/Thumb2/v8_IT_5.ll
+++ b/llvm/test/CodeGen/Thumb2/v8_IT_5.ll
@@ -1,5 +1,5 @@
-; RUN: llc < %s -mtriple=thumbv8 | FileCheck %s
-; RUN: llc < %s -mtriple=thumbv7 -arm-restrict-it | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv8 -arm-atomic-cfg-tidy=0 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7 -arm-atomic-cfg-tidy=0 -arm-restrict-it | FileCheck %s
 ; CHECK: it	ne
 ; CHECK-NEXT: cmpne
 ; CHECK-NEXT: bne [[JUMPTARGET:.LBB[0-9]+_[0-9]+]]