Don't require 16-byte CAS on x86. (#173)

* Don't require 16-byte CAS on x86.

We only need to CAS 2 pointers, which is always possible on x86.

* Fix the way the Image variable is referenced.

* Replace failOnStderr by `set -eo pipefail` on Linux.

The x86 image doesn't have clangformat, which causes cmake to print a
warning on the stderr. Exit codes should be enough to detect failure.

* Use x86 images from snmallocciteam.

* clang-format

azure-pipelines.yml

@@ -9,97 +9,123 @@ jobs:
   displayName: Linux
   pool:
     vmImage: 'ubuntu-18.04'
-  container: snmallocciteam/build_linux_x64:latest
 
   strategy:
     matrix:
-      Clang-7 Debug:
+      64-bit Clang-7 Debug:
         CC: clang-7
         CXX: clang++-7
         BuildType: Debug
         SelfHost: false
         CMakeArgs: ''
+        Image: snmallocciteam/build_linux_x64:latest
 
-      Clang-7 Release:
+      64-bit Clang-7 Release:
         CC: clang-7
         CXX: clang++-7
         BuildType: Release
         SelfHost: false
         CMakeArgs: ''
+        Image: snmallocciteam/build_linux_x64:latest
 
-      Clang-8 Debug:
+      64-bit Clang-8 Debug:
         CC: clang-8
         CXX: clang++-8
         BuildType: Debug
         SelfHost: false
         CMakeArgs: ''
+        Image: snmallocciteam/build_linux_x64:latest
 
-      Clang-8 Release:
+      64-bit Clang-8 Release:
         CC: clang-8
         CXX: clang++-8
         BuildType: Release
         SelfHost: false
         CMakeArgs: ''
+        Image: snmallocciteam/build_linux_x64:latest
 
-      Clang-9 Debug:
+      64-bit Clang-9 Debug:
         CC: clang-9
         CXX: clang++-9
         BuildType: Debug
         SelfHost: false
         CMakeArgs: ''
+        Image: snmallocciteam/build_linux_x64:latest
 
-      Clang-9 Release:
+      64-bit Clang-9 Release:
         CC: clang-9
         CXX: clang++-9
         BuildType: Release
         SelfHost: false
         CMakeArgs: ''
+        Image: snmallocciteam/build_linux_x64:latest
 
-      GCC-8 Debug:
+      64-bit GCC-8 Debug:
         CC: gcc-8
         CXX: g++-8
         BuildType: Debug
         SelfHost: false
         CMakeArgs: ''
+        Image: snmallocciteam/build_linux_x64:latest
 
-      GCC-8 Release:
+      64-bit GCC-8 Release:
         CC: gcc-8
         CXX: g++-8
         BuildType: Release
         SelfHost: false
         CMakeArgs: ''
+        Image: snmallocciteam/build_linux_x64:latest
 
-      Self Host:
+      64-bit Self Host:
         CC: clang-7
         CXX: clang++-7
         BuildType: Debug
         SelfHost: true
         CMakeArgs: ''
+        Image: snmallocciteam/build_linux_x64:latest
 
-      Cache Friendly:
+      64-bit Cache Friendly:
         CC: clang-7
         CXX: clang++-7
         BuildType: Debug
         SelfHost: false
         CMakeArgs: '-DCACHE_FRIENDLY_OFFSET=64'
+        Image: snmallocciteam/build_linux_x64:latest
 
+      32-bit Clang-9 Debug:
+        CC: clang-9
+        CXX: clang++-9
+        BuildType: Debug
+        SelfHost: false
+        CMakeArgs: ''
+        Image: snmallocciteam/build_linux_x86:latest
+
+      32-bit Clang-9 Release:
+        CC: clang-9
+        CXX: clang++-9
+        BuildType: Release
+        SelfHost: false
+        CMakeArgs: ''
+        Image: snmallocciteam/build_linux_x86:latest
+
+  container: $[ variables['Image'] ]
   steps:
   - script: |
+      set -eo pipefail
       ci/scripts/build.sh
     env:
       CC: $(CC)
       CXX: $(CXX)
       BUILD_TYPE: $(BuildType)
       CMAKE_ARGS: $(CMakeArgs)
-    failOnStderr: true
     displayName: 'Build'
 
   - script: |
+      set -eo pipefail
       ci/scripts/test.sh
     env:
       SELF_HOST: $(SelfHost)
       BUILD_TYPE: $(BuildType)
-    failOnStderr: true
     displayName: 'Test'
 
 - job:

ci/linux_x86

@@ -0,0 +1,7 @@
+FROM multiarch/ubuntu-core:x86-bionic
+
+WORKDIR /src
+
+RUN apt update \
+    && apt install --no-install-recommends -y ninja-build clang++-9 cmake \
+    && apt -y clean

src/ds/aba.h

@@ -99,9 +99,11 @@ namespace snmalloc
           (__int64)value,
           (__int64*)&old);
 #  else
-#    if defined(__GNUC__) && !defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_16)
+#    if defined(__GNUC__) && defined(SNMALLOC_VA_BITS_64) && \
+      !defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_16)
 #error You must compile with -mcx16 to enable 16-byte atomic compare and swap.
 #    endif
+
         Linked xchg{value, old.aba + 1};
         std::atomic<Linked>& addr = parent->linked;