[ARM] Add an extra constant hoisting test. NFC

This adds a simple extra test for constant hoisting to show it's
usefulness with constant addresses like those seen in memory
mapped registers in embedded systems.

llvm-svn: 358114

diff --git a/llvm/test/CodeGen/Thumb/consthoist-physical-addr.ll b/llvm/test/CodeGen/Thumb/consthoist-physical-addr.ll
new file mode 100644 (file)
index 0000000..83dc793
--- /dev/null
+++ b/llvm/test/CodeGen/Thumb/consthoist-physical-addr.ll
@@ -0,0 +1,75 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc %s -o - -asm-verbose=false | FileCheck %s
+
+target datalayout = "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64"
+target triple = "thumbv6m-arm-none-eabi"
+
+define i32 @C(i32 %x, i32* nocapture %y) #0 {
+; CHECK-LABEL: C:
+; CHECK:         .save {r4, r5, r7, lr}
+; CHECK-NEXT:    push {r4, r5, r7, lr}
+; CHECK-NEXT:    movs r2, #0
+; CHECK-NEXT:    ldr r3, .LCPI0_0
+; CHECK-NEXT:    b .LBB0_4
+; CHECK-NEXT:  .LBB0_1:
+; CHECK-NEXT:    movs r4, #0
+; CHECK-NEXT:    str r4, [r3, #8]
+; CHECK-NEXT:    lsls r4, r2, #2
+; CHECK-NEXT:    adds r5, r4, r0
+; CHECK-NEXT:    str r5, [r3]
+; CHECK-NEXT:    movs r5, #1
+; CHECK-NEXT:    str r5, [r3, #12]
+; CHECK-NEXT:    isb sy
+; CHECK-NEXT:  .LBB0_2:
+; CHECK-NEXT:    ldr r5, [r3, #12]
+; CHECK-NEXT:    cmp r5, #0
+; CHECK-NEXT:    bne .LBB0_2
+; CHECK-NEXT:    ldr r5, [r3, #4]
+; CHECK-NEXT:    str r5, [r1, r4]
+; CHECK-NEXT:    adds r2, r2, #1
+; CHECK-NEXT:  .LBB0_4:
+; CHECK-NEXT:    cmp r2, #128
+; CHECK-NEXT:    bne .LBB0_1
+; CHECK-NEXT:    movs r0, #0
+; CHECK-NEXT:    pop {r4, r5, r7, pc}
+; CHECK-NEXT:    .p2align 2
+; CHECK-NEXT:  .LCPI0_0:
+; CHECK-NEXT:    .long 805355524
+entry:
+  br label %for.cond
+
+for.cond:                                         ; preds = %B.exit, %entry
+  %i.0 = phi i32 [ 0, %entry ], [ %inc, %B.exit ]
+  %exitcond = icmp eq i32 %i.0, 128
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.body:                                         ; preds = %for.cond
+  %mul = shl i32 %i.0, 2
+  %add = add i32 %mul, %x
+  store volatile i32 0, i32* inttoptr (i32 805355532 to i32*), align 4
+  store volatile i32 %add, i32* inttoptr (i32 805355524 to i32*), align 4
+  store volatile i32 1, i32* inttoptr (i32 805355536 to i32*), align 16
+  tail call void @llvm.arm.isb(i32 15) #1
+  br label %while.cond.i
+
+while.cond.i:                                     ; preds = %while.cond.i, %for.body
+  %0 = load volatile i32, i32* inttoptr (i32 805355536 to i32*), align 16
+  %tobool.i = icmp eq i32 %0, 0
+  br i1 %tobool.i, label %B.exit, label %while.cond.i
+
+B.exit:                                           ; preds = %while.cond.i
+  %1 = load volatile i32, i32* inttoptr (i32 805355528 to i32*), align 8
+  %arrayidx = getelementptr inbounds i32, i32* %y, i32 %i.0
+  store i32 %1, i32* %arrayidx, align 4
+  %inc = add nuw nsw i32 %i.0, 1
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  ret i32 0
+}
+
+; Function Attrs: nounwind
+declare void @llvm.arm.isb(i32) #1
+
+attributes #0 = { minsize nounwind optsize }
+attributes #1 = { nounwind }