[SVE] Precommit test to show missing initialisation of call operand.

When calling func_f8_and_v0_passed_via_memory the memory used to
hold the first vector operand is allocated but not initialised.

llvm/test/CodeGen/AArch64/sve-calling-convention-mixed.ll

@@ -64,13 +64,13 @@ define float @foo2(ptr %x0, ptr %x1) nounwind {
 ; CHECK-NEXT:    ld4d { z16.d - z19.d }, p0/z, [x1]
 ; CHECK-NEXT:    fmov s0, #1.00000000
 ; CHECK-NEXT:    mov w0, wzr
-; CHECK-NEXT:    mov w1, #1
-; CHECK-NEXT:    mov w2, #2
-; CHECK-NEXT:    mov w3, #3
-; CHECK-NEXT:    mov w4, #4
-; CHECK-NEXT:    mov w5, #5
-; CHECK-NEXT:    mov w6, #6
-; CHECK-NEXT:    mov w7, #7
+; CHECK-NEXT:    mov w1, #1 // =0x1
+; CHECK-NEXT:    mov w2, #2 // =0x2
+; CHECK-NEXT:    mov w3, #3 // =0x3
+; CHECK-NEXT:    mov w4, #4 // =0x4
+; CHECK-NEXT:    mov w5, #5 // =0x5
+; CHECK-NEXT:    mov w6, #6 // =0x6
+; CHECK-NEXT:    mov w7, #7 // =0x7
 ; CHECK-NEXT:    add x9, sp, #16
 ; CHECK-NEXT:    ptrue p0.d
 ; CHECK-NEXT:    st1d { z16.d }, p0, [x9]
@@ -694,6 +694,36 @@ define <vscale x 4 x float> @sve_ret_caller_non_sve_callee_high_range()  {
   ret <vscale x 4 x float> undef
 }
 
+declare void @func_f8_and_v0_passed_via_memory(float %f0, float %f1, float %f2, float %f3, float %f4, float %f5, float %f6, float %f7, float %f8, <vscale x 4 x float> %v0)
+define void @verify_all_operands_are_initialised() {
+; CHECK-LABEL: verify_all_operands_are_initialised:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    stp x29, x30, [sp, #-16]! // 16-byte Folded Spill
+; CHECK-NEXT:    addvl sp, sp, #-1
+; CHECK-NEXT:    sub sp, sp, #16
+; CHECK-NEXT:    .cfi_escape 0x0f, 0x0c, 0x8f, 0x00, 0x11, 0x20, 0x22, 0x11, 0x08, 0x92, 0x2e, 0x00, 0x1e, 0x22 // sp + 32 + 8 * VG
+; CHECK-NEXT:    .cfi_offset w30, -8
+; CHECK-NEXT:    .cfi_offset w29, -16
+; CHECK-NEXT:    movi d0, #0000000000000000
+; CHECK-NEXT:    mov w8, #1090519040 // =0x41000000
+; CHECK-NEXT:    fmov s1, #1.00000000
+; CHECK-NEXT:    fmov s2, #2.00000000
+; CHECK-NEXT:    fmov s3, #3.00000000
+; CHECK-NEXT:    fmov s4, #4.00000000
+; CHECK-NEXT:    fmov s5, #5.00000000
+; CHECK-NEXT:    fmov s6, #6.00000000
+; CHECK-NEXT:    fmov s7, #7.00000000
+; CHECK-NEXT:    add x0, sp, #16
+; CHECK-NEXT:    str w8, [sp]
+; CHECK-NEXT:    bl func_f8_and_v0_passed_via_memory
+; CHECK-NEXT:    addvl sp, sp, #1
+; CHECK-NEXT:    add sp, sp, #16
+; CHECK-NEXT:    ldp x29, x30, [sp], #16 // 16-byte Folded Reload
+; CHECK-NEXT:    ret
+  call void @func_f8_and_v0_passed_via_memory(float 0.0, float 1.0, float 2.0, float 3.0, float 4.0, float 5.0, float 6.0, float 7.0, float 8.0, <vscale x 4 x float> shufflevector (<vscale x 4 x float> insertelement (<vscale x 4 x float> poison, float 9.000000e+00, i64 0), <vscale x 4 x float> poison, <vscale x 4 x i32> zeroinitializer))
+  ret void
+}
+
 declare float @callee1(float, <vscale x 8 x double>, <vscale x 8 x double>, <vscale x 2 x double>)
 declare float @callee2(i32, i32, i32, i32, i32, i32, i32, i32, float, <vscale x 8 x double>, <vscale x 8 x double>)
 declare float @callee3(float, float, <vscale x 8 x double>, <vscale x 6 x double>, <vscale x 2 x double>)