This patch adds alignment information for long double to the 64-bit PowerPC

ELF subtarget.

The existing logic is used as a fallback to avoid any changes to the Darwin
ABI.  PPC64 ELF now has two possible data layout strings: one for FreeBSD,
which requires 8-byte alignment, and a default string that requires
16-byte alignment.

I've added a test for PPC64 Linux to verify the 16-byte alignment.  If
somebody wants to add a separate test for FreeBSD, that would be great.

Note that there is a companion patch to update the alignment information
in Clang, which I am committing now as well.

llvm-svn: 166928

1 files changed, 26 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/PowerPC/ppc64-align-long-double.ll b/llvm/test/CodeGen/PowerPC/ppc64-align-long-double.ll
new file mode 100644
index 00000000000..10b70d02e5c
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/ppc64-align-long-double.ll
@@ -0,0 +1,26 @@
+; RUN: llc -mcpu=pwr7 -O0 < %s | FileCheck %s
+
+; Verify internal alignment of long double in a struct.  The double
+; argument comes in in GPR3; GPR4 is skipped; GPRs 5 and 6 contain
+; the long double.  Check that these are stored to proper locations
+; in the parameter save area and loaded from there for return in FPR1/2.
+
+target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-f128:128:128-v128:128:128-n32:64"
+target triple = "powerpc64-unknown-linux-gnu"
+
+%struct.S = type { double, ppc_fp128 }
+
+define ppc_fp128 @test(%struct.S* byval %x) nounwind {
+entry:
+  %b = getelementptr inbounds %struct.S* %x, i32 0, i32 1
+  %0 = load ppc_fp128* %b, align 16
+  ret ppc_fp128 %0
+}
+
+; CHECK: std 6, 72(1)
+; CHECK: std 5, 64(1)
+; CHECK: std 4, 56(1)
+; CHECK: std 3, 48(1)
+; CHECK: lfd 1, 64(1)
+; CHECK: lfd 2, 72(1)
+