llvm/test/CodeGen/WebAssembly/phi.ll
Dan Gohman 1a513a6964 [WebAssembly] Optimize away return instructions using fallthroughs.
This saves a small amount of code size, and is a first small step toward
passing values on the stack across block boundaries.

Differential Review: http://reviews.llvm.org/D20450


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@270294 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-21 00:21:56 +00:00

48 lines
1.1 KiB
LLVM

; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -verify-machineinstrs | FileCheck %s
; Test that phis are lowered.
target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
target triple = "wasm32-unknown-unknown"
; Basic phi triangle.
; CHECK-LABEL: test0:
; CHECK: div_s $[[NUM0:[0-9]+]]=, $0, $pop[[NUM1:[0-9]+]]{{$}}
; CHECK: return $[[NUM0]]{{$}}
define i32 @test0(i32 %p) {
entry:
%t = icmp slt i32 %p, 0
br i1 %t, label %true, label %done
true:
%a = sdiv i32 %p, 3
br label %done
done:
%s = phi i32 [ %a, %true ], [ %p, %entry ]
ret i32 %s
}
; Swap phis.
; CHECK-LABEL: test1:
; CHECK: .LBB1_1:
; CHECK: copy_local $[[NUM0:[0-9]+]]=, $[[NUM1:[0-9]+]]{{$}}
; CHECK: copy_local $[[NUM1]]=, $[[NUM2:[0-9]+]]{{$}}
; CHECK: copy_local $[[NUM2]]=, $[[NUM0]]{{$}}
define i32 @test1(i32 %n) {
entry:
br label %loop
loop:
%a = phi i32 [ 0, %entry ], [ %b, %loop ]
%b = phi i32 [ 1, %entry ], [ %a, %loop ]
%i = phi i32 [ 0, %entry ], [ %i.next, %loop ]
%i.next = add i32 %i, 1
%t = icmp slt i32 %i.next, %n
br i1 %t, label %loop, label %exit
exit:
ret i32 %a
}