llvm/test/CodeGen/WebAssembly/dead-vreg.ll
Dan Gohman 21495bccdc [WebAssembly] Rematerialize constants rather than hold them live in registers.
Teach the register stackifier to rematerialize constants that have multiple
uses instead of leaving them in registers. In the WebAssembly encoding, it's
the same code size to materialize most constants as it is to read a value
from a register.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258142 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-19 16:59:23 +00:00

52 lines
1.5 KiB
LLVM

; RUN: llc < %s -asm-verbose=false -verify-machineinstrs | FileCheck %s
; Check that unused vregs aren't assigned registers.
target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
target triple = "wasm32-unknown-unknown"
define void @foo(i32* nocapture %a, i32 %w, i32 %h) {
; CHECK-LABEL: foo:
; CHECK-NEXT: .param i32, i32, i32{{$}}
; CHECK-NEXT: .local i32, i32, i32, i32, i32, i32{{$}}
entry:
%cmp.19 = icmp sgt i32 %h, 0
br i1 %cmp.19, label %for.cond.1.preheader.lr.ph, label %for.end.7
for.cond.1.preheader.lr.ph:
%cmp2.17 = icmp sgt i32 %w, 0
br label %for.cond.1.preheader
for.cond.1.preheader:
%y.020 = phi i32 [ 0, %for.cond.1.preheader.lr.ph ], [ %inc6, %for.inc.5 ]
br i1 %cmp2.17, label %for.body.3.lr.ph, label %for.inc.5
for.body.3.lr.ph:
%mul4 = mul nsw i32 %y.020, %w
br label %for.body.3
for.body.3:
%x.018 = phi i32 [ 0, %for.body.3.lr.ph ], [ %inc, %for.body.3 ]
%mul = mul nsw i32 %x.018, %y.020
%add = add nsw i32 %x.018, %mul4
%arrayidx = getelementptr inbounds i32, i32* %a, i32 %add
store i32 %mul, i32* %arrayidx, align 4
%inc = add nuw nsw i32 %x.018, 1
%exitcond = icmp eq i32 %inc, %w
br i1 %exitcond, label %for.inc.5.loopexit, label %for.body.3
for.inc.5.loopexit:
br label %for.inc.5
for.inc.5:
%inc6 = add nuw nsw i32 %y.020, 1
%exitcond22 = icmp eq i32 %inc6, %h
br i1 %exitcond22, label %for.end.7.loopexit, label %for.cond.1.preheader
for.end.7.loopexit:
br label %for.end.7
for.end.7:
ret void
}