llvm/test/CodeGen/X86/pr32256.ll
Matt Arsenault 5fd17c6d29 RegAllocFast: Improve hinting heuristic
Trace through multiple COPYs when looking for a physreg source. Add
hinting for vregs that will be copied into physregs (we only hinted
for vregs getting copied to a physreg previously).  Give hinted a
register a bonus when deciding which value to spill.  This is part of
my rewrite regallocfast series. In fact this one doesn't even have an
effect unless you also flip the allocation to happen from back to
front of a basic block. Nonetheless it helps to split this up to ease
review of D52010

Patch by Matthias Braun

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360887 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-16 12:50:39 +00:00

48 lines
1.6 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -fast-isel -mtriple=i686-unknown-unknown -O0 -mcpu=skx | FileCheck %s
@c = external global i8, align 1
; Function Attrs: noinline nounwind
define void @_Z1av() {
; CHECK-LABEL: _Z1av:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: subl $2, %esp
; CHECK-NEXT: .cfi_def_cfa_offset 6
; CHECK-NEXT: xorl %eax, %eax
; CHECK-NEXT: # kill: def $al killed $al killed $eax
; CHECK-NEXT: movb c, %cl
; CHECK-NEXT: xorb $-1, %cl
; CHECK-NEXT: testb $1, %cl
; CHECK-NEXT: movb %al, (%esp) # 1-byte Spill
; CHECK-NEXT: jne .LBB0_1
; CHECK-NEXT: jmp .LBB0_2
; CHECK-NEXT: .LBB0_1: # %land.rhs
; CHECK-NEXT: xorl %eax, %eax
; CHECK-NEXT: # kill: def $al killed $al killed $eax
; CHECK-NEXT: movb %al, (%esp) # 1-byte Spill
; CHECK-NEXT: jmp .LBB0_2
; CHECK-NEXT: .LBB0_2: # %land.end
; CHECK-NEXT: movb (%esp), %al # 1-byte Reload
; CHECK-NEXT: andb $1, %al
; CHECK-NEXT: movb %al, {{[0-9]+}}(%esp)
; CHECK-NEXT: addl $2, %esp
; CHECK-NEXT: .cfi_def_cfa_offset 4
; CHECK-NEXT: retl
entry:
%b = alloca i8, align 1
%0 = load i8, i8* @c, align 1
%tobool = trunc i8 %0 to i1
%lnot = xor i1 %tobool, true
br i1 %lnot, label %land.rhs, label %land.end
land.rhs: ; preds = %entry
br label %land.end
land.end: ; preds = %land.rhs, %entry
%1 = phi i1 [ false, %entry ], [ false, %land.rhs ]
%conv = zext i1 %1 to i8
store i8 %conv, i8* %b, align 1
ret void
}