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; RUN: llc < %s -asm-verbose=false | FileCheck %s
; Test the register stackifier pass.
target datalayout = "e-p:32:32-i64:64-n32:64-S128"
target triple = "wasm32-unknown-unknown"
; No because of pointer aliasing.
; CHECK-LABEL: no0:
; CHECK: return $1{{$}}
define i32 @no0(i32* %p, i32* %q) {
%t = load i32, i32* %q
store i32 0, i32* %p
ret i32 %t
}
; No because of side effects.
; CHECK-LABEL: no1:
; CHECK: return $1{{$}}
define i32 @no1(i32* %p, i32* dereferenceable(4) %q) {
%t = load volatile i32, i32* %q, !invariant.load !0
store volatile i32 0, i32* %p
ret i32 %t
}
; Yes because of invariant load and no side effects.
; CHECK-LABEL: yes0:
; CHECK: return $pop0{{$}}
define i32 @yes0(i32* %p, i32* dereferenceable(4) %q) {
%t = load i32, i32* %q, !invariant.load !0
store i32 0, i32* %p
ret i32 %t
}
; Yes because of no intervening side effects.
; CHECK-LABEL: yes1:
; CHECK: return $pop0{{$}}
define i32 @yes1(i32* %q) {
%t = load volatile i32, i32* %q
ret i32 %t
}
; Don't schedule stack uses into the stack. To reduce register pressure, the
; scheduler might be tempted to move the definition of $2 down. However, this
; would risk getting incorrect liveness if the instructions are later
; rearranged to make the stack contiguous.
; CHECK-LABEL: stack_uses:
; CHECK-NEXT: .param i32{{$}}
; CHECK-NEXT: .result i32{{$}}
; CHECK-NEXT: local i32, i32{{$}}
; CHECK-NEXT: i32.const $1=, 1{{$}}
; CHECK-NEXT: i32.const $2=, 0{{$}}
; CHECK-NEXT: i32.and $push0=, $0, $1{{$}}
; CHECK-NEXT: i32.eq $push1=, $pop0, $2{{$}}
; CHECK-NEXT: block BB4_2{{$}}
; CHECK-NEXT: br_if $pop1, BB4_2{{$}}
; CHECK-NEXT: return $2{{$}}
; CHECK-NEXT: BB4_2:{{$}}
; CHECK-NEXT: return $1{{$}}
define i32 @stack_uses(i32 %x) {
entry:
%c = trunc i32 %x to i1
br i1 %c, label %true, label %false
true:
ret i32 0
false:
ret i32 1
}
!0 = !{}
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