add generic x86_32 support (#52634)

* add generic x86_32 support

- Add support for i386-i586.
- Add `isx86_32` predicate that can replace most uses of `isi686`.
- `isi686` is reinterpreted to mean "exactly i686 arch, and not say i585 or i386".
- This branch was used to build working i586 kernel running on i586 hardware.

* revert `isi[345]86`, remove dead code

- Remove changes to dead code in `doubles.nix` and `for-meta.nix`.
- Remove `isi[345]86` predicates since other cpu families don't have specific model predicates.

* remove i386-linux since linux not supported on that cpu

9 files changed, 11 insertions, 9 deletions

diff --git a/pkgs/build-support/bintools-wrapper/default.nix b/pkgs/build-support/bintools-wrapper/default.nix
index 620ea530fc55..4122af898de9 100644
--- a/pkgs/build-support/bintools-wrapper/default.nix
+++ b/pkgs/build-support/bintools-wrapper/default.nix
@@ -177,7 +177,7 @@ stdenv.mkDerivation {
       /**/ if targetPlatform.isAarch64 then endianPrefix + "aarch64"
       else if targetPlatform.isAarch32     then endianPrefix + "arm"
       else if targetPlatform.isx86_64  then "x86-64"
-      else if targetPlatform.isx86     then "i386"
+      else if targetPlatform.isx86_32  then "i386"
       else if targetPlatform.isMips    then {
           "mips"     = "btsmipn32"; # n32 variant
           "mipsel"   = "ltsmipn32"; # n32 variant
diff --git a/pkgs/development/compilers/gcc/4.8/default.nix b/pkgs/development/compilers/gcc/4.8/default.nix
index 6467cfc801dc..b36529ecb3cf 100644
--- a/pkgs/development/compilers/gcc/4.8/default.nix
+++ b/pkgs/development/compilers/gcc/4.8/default.nix
@@ -312,7 +312,7 @@ stdenv.mkDerivation ({
     optional (!bootstrap) "--disable-bootstrap" ++
 
     # Platform-specific flags
-    optional (targetPlatform == hostPlatform && targetPlatform.isi686) "--with-arch=i686" ++
+    optional (targetPlatform == hostPlatform && targetPlatform.isx86_32) "--with-arch=${stdenv.hostPlatform.parsed.cpu.name}" ++
     optionals hostPlatform.isSunOS [
       "--enable-long-long" "--enable-libssp" "--enable-threads=posix" "--disable-nls" "--enable-__cxa_atexit"
       # On Illumos/Solaris GNU as is preferred
diff --git a/pkgs/development/compilers/gcc/4.9/default.nix b/pkgs/development/compilers/gcc/4.9/default.nix
index 1676668d9111..ee00a3aee1e1 100644
--- a/pkgs/development/compilers/gcc/4.9/default.nix
+++ b/pkgs/development/compilers/gcc/4.9/default.nix
@@ -325,7 +325,7 @@ stdenv.mkDerivation ({
     optional (!bootstrap) "--disable-bootstrap" ++
 
     # Platform-specific flags
-    optional (targetPlatform == hostPlatform && targetPlatform.isi686) "--with-arch=i686" ++
+    optional (targetPlatform == hostPlatform && targetPlatform.isx86_32) "--with-arch=${stdenv.hostPlatform.parsed.cpu.name}" ++
     optionals hostPlatform.isSunOS [
       "--enable-long-long" "--enable-libssp" "--enable-threads=posix" "--disable-nls" "--enable-__cxa_atexit"
       # On Illumos/Solaris GNU as is preferred
diff --git a/pkgs/development/compilers/gcc/5/default.nix b/pkgs/development/compilers/gcc/5/default.nix
index 6049cdcb6e8a..15f95ef205eb 100644
--- a/pkgs/development/compilers/gcc/5/default.nix
+++ b/pkgs/development/compilers/gcc/5/default.nix
@@ -324,7 +324,7 @@ stdenv.mkDerivation ({
     optional (!bootstrap) "--disable-bootstrap" ++
 
     # Platform-specific flags
-    optional (targetPlatform == hostPlatform && targetPlatform.isi686) "--with-arch=i686" ++
+    optional (targetPlatform == hostPlatform && targetPlatform.isx86_32) "--with-arch=${stdenv.hostPlatform.parsed.cpu.name}" ++
     optionals hostPlatform.isSunOS [
       "--enable-long-long" "--enable-libssp" "--enable-threads=posix" "--disable-nls" "--enable-__cxa_atexit"
       # On Illumos/Solaris GNU as is preferred
diff --git a/pkgs/development/compilers/gcc/6/default.nix b/pkgs/development/compilers/gcc/6/default.nix
index a467527c613e..adaf4e36ce96 100644
--- a/pkgs/development/compilers/gcc/6/default.nix
+++ b/pkgs/development/compilers/gcc/6/default.nix
@@ -326,7 +326,7 @@ stdenv.mkDerivation ({
     optional (!bootstrap) "--disable-bootstrap" ++
 
     # Platform-specific flags
-    optional (targetPlatform == hostPlatform && targetPlatform.isi686) "--with-arch=i686" ++
+    optional (targetPlatform == hostPlatform && targetPlatform.isx86_32) "--with-arch=${stdenv.hostPlatform.parsed.cpu.name}" ++
     optionals hostPlatform.isSunOS [
       "--enable-long-long" "--enable-libssp" "--enable-threads=posix" "--disable-nls" "--enable-__cxa_atexit"
       # On Illumos/Solaris GNU as is preferred
diff --git a/pkgs/development/compilers/gcc/7/default.nix b/pkgs/development/compilers/gcc/7/default.nix
index 41af804e551f..956f357f84c6 100644
--- a/pkgs/development/compilers/gcc/7/default.nix
+++ b/pkgs/development/compilers/gcc/7/default.nix
@@ -289,7 +289,7 @@ stdenv.mkDerivation ({
     optional (!bootstrap) "--disable-bootstrap" ++
 
     # Platform-specific flags
-    optional (targetPlatform == hostPlatform && targetPlatform.isi686) "--with-arch=i686" ++
+    optional (targetPlatform == hostPlatform && targetPlatform.isx86_32) "--with-arch=${stdenv.hostPlatform.parsed.cpu.name}" ++
     optionals hostPlatform.isSunOS [
       "--enable-long-long" "--enable-libssp" "--enable-threads=posix" "--disable-nls" "--enable-__cxa_atexit"
       # On Illumos/Solaris GNU as is preferred
diff --git a/pkgs/development/compilers/gcc/8/default.nix b/pkgs/development/compilers/gcc/8/default.nix
index 80d57c9d538c..66b98cc6d64c 100644
--- a/pkgs/development/compilers/gcc/8/default.nix
+++ b/pkgs/development/compilers/gcc/8/default.nix
@@ -277,7 +277,7 @@ stdenv.mkDerivation ({
     optional (!bootstrap) "--disable-bootstrap" ++
 
     # Platform-specific flags
-    optional (targetPlatform == hostPlatform && targetPlatform.isi686) "--with-arch=i686" ++
+    optional (targetPlatform == hostPlatform && targetPlatform.isx86_32) "--with-arch=${stdenv.hostPlatform.parsed.cpu.name}" ++
     optionals hostPlatform.isSunOS [
       "--enable-long-long" "--enable-libssp" "--enable-threads=posix" "--disable-nls" "--enable-__cxa_atexit"
       # On Illumos/Solaris GNU as is preferred
diff --git a/pkgs/development/compilers/llvm/7/llvm.nix b/pkgs/development/compilers/llvm/7/llvm.nix
index bff89812cae8..6253162f254c 100644
--- a/pkgs/development/compilers/llvm/7/llvm.nix
+++ b/pkgs/development/compilers/llvm/7/llvm.nix
@@ -134,7 +134,7 @@ in stdenv.mkDerivation (rec {
     ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${release_version}.dylib
   '';
 
-  doCheck = stdenv.isLinux && (!stdenv.isi686);
+  doCheck = stdenv.isLinux && (!stdenv.isx86_32);
 
   checkTarget = "check-all";
 
diff --git a/pkgs/stdenv/generic/default.nix b/pkgs/stdenv/generic/default.nix
index f77f43aea886..fccab8f60ff2 100644
--- a/pkgs/stdenv/generic/default.nix
+++ b/pkgs/stdenv/generic/default.nix
@@ -122,7 +122,9 @@ let
       # Utility flags to test the type of platform.
       inherit (hostPlatform)
         isDarwin isLinux isSunOS isCygwin isFreeBSD isOpenBSD
-        isi686 isx86_64 is64bit isAarch32 isAarch64 isMips isBigEndian;
+        isi686 isx86_32 isx86_64
+        is32bit is64bit
+        isAarch32 isAarch64 isMips isBigEndian;
       isArm = lib.warn
         "`stdenv.isArm` is deprecated after 18.03. Please use `stdenv.isAarch32` instead"
         hostPlatform.isAarch32;