Add macOS x86-64, Linux AArch64, and Linux x86 CI jobs

.github/workflows/CI.yml

@@ -17,21 +17,17 @@ jobs:
           - '1'
           - 'nightly'
         os:
-          - ubuntu-latest
-          - macOS-latest
-          - windows-latest
+          - ubuntu-latest     # x86-64
+          - ubuntu-26.04-arm  # aarch64
+          - macOS-latest      # aarch64
+          - macos-26-intel    # x86-64
+          - windows-latest    # x86-64
         arch:
-          - x64
-          - aarch64
-        exclude:
-          # macOS-latest is Apple Silicon (arm64), so x64 is not available there.
-          - os: macOS-latest
-            arch: x64
-          # ubuntu-latest and windows-latest runners are x64-only.
+          - default
+        include:
           - os: ubuntu-latest
-            arch: aarch64
-          - os: windows-latest
-            arch: aarch64
+            arch: x86
+            version: '1'
     steps:
       - uses: actions/checkout@v7
       - uses: julia-actions/setup-julia@v3

README.md

@@ -6,11 +6,9 @@ This is a Julia interface to the IEEE 754 binary128 floating point format, backe
 
 ## Support
 
-Quadmath supports x86_64 and AArch64.
+Quadmath supports x86_64, x86, and AArch64.
 
 - On AArch64 Linux and FreeBSD, libquadmath is not available, so `long double` functions from libm are used instead. Unlike x86_64, `long double` on AArch64 is IEEE 754 binary128.
-- On x86_64, it may require gcc 4.3 or later for the `__float128` type.
-- It has not been tested on 32-bit x86 Linux.
 - It does not work on 32-bit ARM due to the lack of libquadmath support for that platform.
 
 ## Installation