Set TargetCPUName for AIX to default to pwr7.

[jamieschmeiser]

Summary

Set the TargetCPUName for AIX to default to pwr7, removing the setting
of it based on the major/minor of the OS version, which previously
set it to pwr4 for AIX 7.1 and earlier. The old code would also set it to
pwr4 when the OS version was not specified and with the change, it will
default it to pwr7 in all cases.

[hubert.reinterpretcast]

LGTM with comment.

clang/test/Driver/aix-mcpu-default.c

9

I suggest this test be modified to check that the target cpu is power7 even when the version level is unspecified.

[ZarkoCA]

Thanks @jamieschmeiser this change LGTM but I'll defer to @hubert.reinterpretcast for final approval.

[jamieschmeiser]

Respond to review comment: expand testing.

clang/lib/Driver/ToolChains/CommonArgs.cpp

std::string tools::getCPUName(const ArgList &Args, const llvm::Triple &T,
   case llvm::Triple::ppc64le: {
     std::string TargetCPUName = ppc::getPPCTargetCPU(Args);
     // LLVM may default to generating code for the native CPU,
     // but, like gcc, we default to a more generic option for
     // each architecture. (except on AIX)
     if (!TargetCPUName.empty())
       return TargetCPUName;
 
-    if (T.isOSAIX()) {
-      unsigned major, minor, unused_micro;
-      T.getOSVersion(major, minor, unused_micro);
-      // The minimal arch level moved from pwr4 for AIX7.1 to
-      // pwr7 for AIX7.2.
-      TargetCPUName =
-          (major < 7 || (major == 7 && minor < 2)) ? "pwr4" : "pwr7";
-    } else if (T.getArch() == llvm::Triple::ppc64le)
+    if (T.isOSAIX())
+      TargetCPUName = "pwr7";
+    else if (T.getArch() == llvm::Triple::ppc64le)
       TargetCPUName = "ppc64le";
     else if (T.getArch() == llvm::Triple::ppc64)
       TargetCPUName = "ppc64";
     else
       TargetCPUName = "ppc";
 
     return TargetCPUName;
   }

clang/test/Driver/aix-mcpu-default.c

 // Check that the target cpu defaults to power7 on AIX7.2 and up.
 // RUN: %clang -no-canonical-prefixes %s -### -c 2>&1 \
 // RUN:        -target powerpc-ibm-aix7.2 \
 // RUN:   | FileCheck --check-prefix=CHECK-MCPU-DEFAULT-AIX72 %s
 // CHECK-MCPU-DEFAULT-AIX72-NOT: warning:
 // CHECK-MCPU-DEFAULT-AIX72:     {{.*}}clang{{.*}}" "-cc1"
 // CHECK-MCPU-DEFAULT-AIX72:     "-target-cpu" "pwr7"
 
-// Check that the target cpu defaults to power4 on AIX7.1 and below.
+// Check that the target cpu defaults to power7 on AIX7.1 and below.
 // RUN: %clang -no-canonical-prefixes %s -### -c 2>&1 \
 // RUN:        -target powerpc-ibm-aix7.1 \
 // RUN:   | FileCheck --check-prefix=CHECK-MCPU-DEFAULT-AIX71 %s
 // CHECK-MCPU-DEFAULT-AIX71-NOT: warning:
 // CHECK-MCPU-DEFAULT-AIX71:     {{.*}}clang{{.*}}" "-cc1"
-// CHECK-MCPU-DEFAULT-AIX71:     "-target-cpu" "pwr4"
+// CHECK-MCPU-DEFAULT-AIX71:     "-target-cpu" "pwr7"
 
 // Check that the user is able to overwrite the default with '-mcpu'.
 // RUN: %clang -no-canonical-prefixes %s -### -c 2>&1 \
 // RUN:        -mcpu=pwr6 \
 // RUN:        -target powerpc-ibm-aix \
 // RUN:   | FileCheck --check-prefix=CHECK-MCPU-USER %s
 // CHECK-MCPU-USER-NOT: warning:
 // CHECK-MCPU-USER:     {{.*}}clang{{.*}}" "-cc1"
 // CHECK-MCPU-USER:     "-target-cpu" "pwr6"