[PowerPC] Generate Power9 extswsli extend sign and shift immediate instruction

Add a DAG combine for the PowerPC code generator to generate the Power9 extswsli
extend sign and shift immediate instruction.

Patch by RolandF.

Differential revision: https://reviews.llvm.org/D49879

llvm-svn: 340016

1 files changed, 17 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/PowerPC/extswsli.ll b/llvm/test/CodeGen/PowerPC/extswsli.ll
new file mode 100644
index 00000000000..62014aa1042
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/extswsli.ll
@@ -0,0 +1,17 @@
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64le-unknown-linux-gnu \
+; RUN:     -mcpu=pwr9 -ppc-asm-full-reg-names < %s | FileCheck %s
+
+@z = external local_unnamed_addr global i32*, align 8
+
+; Function Attrs: norecurse nounwind readonly
+define signext i32 @_Z2tcii(i32 signext %x, i32 signext %y) local_unnamed_addr #0 {
+entry:
+  %0 = load i32*, i32** @z, align 8
+  %add = add nsw i32 %y, %x
+  %idxprom = sext i32 %add to i64
+  %arrayidx = getelementptr inbounds i32, i32* %0, i64 %idxprom
+  %1 = load i32, i32* %arrayidx, align 4
+  ret i32 %1
+; CHECK-LABEL: @_Z2tcii
+; CHECK: extswsli {{r[0-9]+}}, {{r[0-9]+}}, 2
+}