[SystemZ] Use STDY/STEY/LDY/LEY for VR32/VR64 in eliminateFrameIndex().
When e.g. a VR64 register is spilled to a stack slot requiring a long
(20-bit) displacement, it is possible to use an FP opcode if the allocated
phys reg allows it. This eliminates the use of a separate LAY instruction.
Reviewed By: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D115406
diff --git a/llvm/test/CodeGen/SystemZ/elim-frame-index-VR.ll b/llvm/test/CodeGen/SystemZ/elim-frame-index-VR.ll
new file mode 100644
index 0000000..50a8ada
--- /dev/null
+++ b/llvm/test/CodeGen/SystemZ/elim-frame-index-VR.ll
@@ -0,0 +1,68 @@
+; RUN: llc < %s -mtriple=s390x-linux-gnu -mcpu=z14 | FileCheck %s
+;
+; Test that a spill/reload of a VR32/VR64 reg uses the FP opcode supporting
+; 20-bit displacement if needed and possible.
+
+define void @f1(i32 %arg, ...) {
+; CHECK-LABEL: f1:
+; CHECK-NOT: lay
+; CHECK: stdy %f0, 4400(%r15)
+bb:
+ %i = alloca [4096 x i8]
+ ret void
+}
+
+define void @f2(float %Arg) {
+; CHECK-LABEL: f2:
+; CHECK-NOT: lay
+; CHECK: stey %f0, 4172(%r15)
+bb:
+ %i = alloca [1000 x float]
+ %i2 = getelementptr inbounds [1000 x float], [1000 x float]* %i, i64 0, i64 999
+ br i1 undef, label %bb3, label %bb2
+
+bb2:
+ store float %Arg , float* %i2
+ br label %bb3
+
+bb3:
+ ret void
+}
+
+define void @f3(double* %Dst) {
+; CHECK-LABEL: f3:
+; CHECK-NOT: lay
+; CHECK: ldy %f0, 4168(%r15)
+bb:
+ %i = alloca [500 x double]
+ br i1 undef, label %bb3, label %bb2
+
+bb2:
+ %i12 = getelementptr inbounds [500 x double], [500 x double]* %i, i64 0, i64 499
+ %i13 = load double, double* %i12
+ %i14 = fdiv double %i13, 0.000000e+00
+ store double %i14, double* %Dst
+ br label %bb3
+
+bb3:
+ ret void
+}
+
+define void @f4(float* %Dst) {
+; CHECK-LABEL: f4:
+; CHECK-NOT: lay
+; CHECK: ley %f0, 4172(%r15)
+bb:
+ %i = alloca [1000 x float]
+ br i1 undef, label %bb3, label %bb2
+
+bb2:
+ %i12 = getelementptr inbounds [1000 x float], [1000 x float]* %i, i64 0, i64 999
+ %i13 = load float, float* %i12
+ %i14 = fdiv float %i13, 0.000000e+00
+ store float %i14, float* %Dst
+ br label %bb3
+
+bb3:
+ ret void
+}
