[PowerPC] Reduce register pressure by not materializing a constant just for use as an index register for X-Form loads/stores.
For this example:
float test (int *arr) {
return arr[2];
}
We currently generate the following code:
li r4, 8
lxsiwax f0, r3, r4
xscvsxdsp f1, f0
With this patch, we will now generate:
addi r3, r3, 8
lxsiwax f0, 0, r3
xscvsxdsp f1, f0
Originally reported in: https://bugs.llvm.org/show_bug.cgi?id=27204
Differential Revision: https://reviews.llvm.org/D35027
llvm-svn: 307553
diff --git a/llvm/test/CodeGen/PowerPC/build-vector-tests.ll b/llvm/test/CodeGen/PowerPC/build-vector-tests.ll
index c42f677..60bec4d 100644
--- a/llvm/test/CodeGen/PowerPC/build-vector-tests.ll
+++ b/llvm/test/CodeGen/PowerPC/build-vector-tests.ll
@@ -1028,7 +1028,7 @@
; P9LE: vperm
; P9LE: blr
; P8BE: sldi {{r[0-9]+}}, r4, 2
-; P8BE-DAG: lxvw4x {{v[0-9]+}}, r3,
+; P8BE-DAG: lxvw4x {{v[0-9]+}}, 0, r3
; P8BE-DAG: lxvw4x
; P8BE: vperm
; P8BE: blr
@@ -2187,7 +2187,7 @@
; P9LE: vperm
; P9LE: blr
; P8BE-DAG: sldi {{r[0-9]+}}, r4, 2
-; P8BE-DAG: lxvw4x {{v[0-9]+}}, r3
+; P8BE-DAG: lxvw4x {{v[0-9]+}}, 0, r3
; P8BE-DAG: lxvw4x
; P8BE: vperm
; P8BE: blr