[Sparc] Account for bias in stack readjustment

Summary: This was broken long ago in D12208, which failed to account for
the fact that 64-bit SPARC uses a stack bias of 2047, and it is the
*unbiased* value which should be aligned, not the biased one. This was
seen to be an issue with Rust.

Patch by: jrtc27 (James Clarke)

Reviewers: jyknight, venkatra

Reviewed By: jyknight

Subscribers: jacob_hansen, JDevlieghere, fhahn, fedor.sergeev, llvm-commits

Differential Revision: https://reviews.llvm.org/D39425

llvm-svn: 323643
diff --git a/llvm/test/CodeGen/SPARC/stack-align.ll b/llvm/test/CodeGen/SPARC/stack-align.ll
index b152e6a..6516fb7 100644
--- a/llvm/test/CodeGen/SPARC/stack-align.ll
+++ b/llvm/test/CodeGen/SPARC/stack-align.ll
@@ -1,4 +1,5 @@
-; RUN: llc -march=sparc < %s | FileCheck %s
+; RUN: llc -march=sparc < %s | FileCheck %s --check-prefixes=CHECK,CHECK32
+; RUN: llc -march=sparcv9 < %s | FileCheck %s --check-prefixes=CHECK,CHECK64
 declare void @stack_realign_helper(i32 %a, i32* %b)
 
 ;; This is a function where we have a local variable of 64-byte
@@ -7,10 +8,15 @@
 ;; the argument is accessed via frame pointer not stack pointer (to %o0).
 
 ;; CHECK-LABEL: stack_realign:
-;; CHECK:      andn %sp, 63, %sp
-;; CHECK-NEXT: ld [%fp+92], %o0
-;; CHECK-NEXT: call stack_realign_helper
-;; CHECK-NEXT: add %sp, 128, %o1
+;; CHECK32:      andn %sp, 63, %sp
+;; CHECK32-NEXT: ld [%fp+92], %o0
+;; CHECK64:      add %sp, 2047, %g1
+;; CHECK64-NEXT: andn %g1, 63, %g1
+;; CHECK64-NEXT: add %g1, -2047, %sp
+;; CHECK64-NEXT: ld [%fp+2227], %o0
+;; CHECK-NEXT:   call stack_realign_helper
+;; CHECK32-NEXT: add %sp, 128, %o1
+;; CHECK64-NEXT: add %sp, 2239, %o1
 
 define void @stack_realign(i32 %a, i32 %b, i32 %c, i32 %d, i32 %e, i32 %f, i32 %g) {
 entry: