llvm-6502/test/CodeGen/X86/2011-09-14-valcoalesce.ll
Tim Northover 15983b80a0 X86: use sub-register sequences for MOV*r0 operations
Instead of having a bunch of separate MOV8r0, MOV16r0, ... pseudo-instructions,
it's better to use a single MOV32r0 (which will expand to "xorl %reg, %reg")
and obtain other sizes with EXTRACT_SUBREG and SUBREG_TO_REG. The encoding is
smaller and partial register updates can sometimes be avoided.

Until recently, this sequence was a barrier to rematerialization though. That
should now be fixed so it's an appropriate time to make the change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182928 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-30 13:19:42 +00:00

196 lines
7.9 KiB
LLVM

; RUN: llc < %s -march=x86 -disable-block-placement | FileCheck %s
;
; Test RegistersDefinedFromSameValue. We have multiple copies of the same vreg:
; while.body85.i:
; vreg1 = copy vreg2
; vreg2 = add
; critical edge from land.lhs.true.i -> if.end117.i:
; vreg27 = vreg2
; critical edge from land.lhs.true103.i -> if.end117.i:
; vreg27 = vreg2
; if.then108.i:
; vreg27 = vreg1
;
; Prior to fixing PR10920 401.bzip miscompile, the coalescer would
; consider vreg1 and vreg27 to be copies of the same value. It would
; then remove one of the critical edge copes, which cannot safely be removed.
; There are two obvious ways the register-allocator could go here, either
; reusing the pre-addition register later, or the post-addition one. Currently,
; it does the latter, so we check:
; CHECK: # %while.body85.i
; CHECK-NOT: # %
; CHECK-NOT: add
; CHECK: movl %[[POSTR:e[abcdxi]+]], %[[PRER:e[abcdxi]+]]
; CHECK: addl %{{.*}}, %[[POSTR]]
; CHECK: # %while.end.i
; CHECK-NOT: movl %[[POSTR]]
; CHECK: # %land.lhs.true.i
; CHECK-NOT: movl %[[POSTR]]
; CHECK: # %land.lhs.true103.i
; CHECK-NOT: movl %[[POSTR]]
; CHECK: # %if.then108.i
; CHECK: movl %[[PRER]], %[[POSTR]]
; CHECK: # %if.end117.i
; and use it for fprintf:
; CHECK: movl %[[POSTR]], 12(%esp)
; If it ever reverts to reusing the pre-addition register then we should
; *probably* check this instead (it certainly worked last time):
; CHECKALT: # %while.body85.i
; CHECKALT-NOT: # %
; CHECKALT-NOT: add
; CHECKALT: movl %[[POSTR:e[abcdxi]+]], %[[PRER:e[abcdxi]+]]
; CHECKALT: addl %{{.*}}, %[[POSTR]]
; CHECKALT: # %while.end.i
; CHECKALT: movl %[[POSTR]], %[[USER:e[abcdxi]+]]
; CHECKALT: # %land.lhs.true.i
; CHECKALT: movl %[[POSTR]], %[[USER]]
; CHECKALT: # %land.lhs.true103.i
; CHECKALT: movl %[[POSTR]], %[[USER]]
; CHECKALT: # %if.then108.i
; [[PRER] live out, so nothing on this path should define it.
; CHECKALT-NOT: , %[[PRER]]
; CHECKALT: # %if.end117.i
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32"
@.str3 = external unnamed_addr constant [59 x i8], align 1
define void @BZ2_compressBlock() nounwind ssp {
entry:
br i1 undef, label %if.then68, label %if.end85
if.then68: ; preds = %entry
br label %for.body.i.i
for.body.i.i: ; preds = %for.inc.i.i, %if.then68
br i1 undef, label %for.inc.i.i, label %if.then.i.i
if.then.i.i: ; preds = %for.body.i.i
br label %for.inc.i.i
for.inc.i.i: ; preds = %if.then.i.i, %for.body.i.i
br i1 undef, label %makeMaps_e.exit.i, label %for.body.i.i
makeMaps_e.exit.i: ; preds = %for.inc.i.i
br i1 undef, label %for.cond19.preheader.i, label %for.cond.for.cond19.preheader_crit_edge.i
for.cond.for.cond19.preheader_crit_edge.i: ; preds = %makeMaps_e.exit.i
unreachable
for.cond19.preheader.i: ; preds = %makeMaps_e.exit.i
br i1 undef, label %for.body25.lr.ph.i, label %for.cond33.preheader.i
for.body25.lr.ph.i: ; preds = %for.cond19.preheader.i
br label %for.body25.i
for.cond33.preheader.i: ; preds = %for.body25.i, %for.cond19.preheader.i
br i1 undef, label %if.then.i, label %if.end.i
for.body25.i: ; preds = %for.body25.i, %for.body25.lr.ph.i
br i1 undef, label %for.body25.i, label %for.cond33.preheader.i
if.then.i: ; preds = %for.cond33.preheader.i
br label %if.end.i
if.end.i: ; preds = %if.then.i, %for.cond33.preheader.i
br i1 undef, label %for.inc27.us.5.i, label %for.end30.i
for.end30.i: ; preds = %for.inc27.us.5.i, %if.end.i
br i1 undef, label %if.end36.i, label %if.then35.i
if.then35.i: ; preds = %for.end30.i
unreachable
if.end36.i: ; preds = %for.end30.i
%sub83.i = add nsw i32 undef, 1
br label %while.body.i188
for.cond182.preheader.i: ; preds = %for.end173.i
br i1 undef, label %for.inc220.us.i, label %while.body300.preheader.i
while.body.i188: ; preds = %for.end173.i, %if.end36.i
%gs.0526.i = phi i32 [ 0, %if.end36.i ], [ %add177.i, %for.end173.i ]
%or.cond514517.i = and i1 false, undef
br i1 %or.cond514517.i, label %while.body85.i, label %if.end117.i
while.body85.i: ; preds = %while.body85.i, %while.body.i188
%aFreq.0518.i = phi i32 [ %add93.i, %while.body85.i ], [ 0, %while.body.i188 ]
%inc87.i = add nsw i32 0, 1
%tmp91.i = load i32* undef, align 4
%add93.i = add nsw i32 %tmp91.i, %aFreq.0518.i
%or.cond514.i = and i1 undef, false
br i1 %or.cond514.i, label %while.body85.i, label %while.end.i
while.end.i: ; preds = %while.body85.i
br i1 undef, label %land.lhs.true.i, label %if.end117.i
land.lhs.true.i: ; preds = %while.end.i
br i1 undef, label %land.lhs.true103.i, label %if.end117.i
land.lhs.true103.i: ; preds = %land.lhs.true.i
br i1 undef, label %if.then108.i, label %if.end117.i
if.then108.i: ; preds = %land.lhs.true103.i
br label %if.end117.i
if.end117.i: ; preds = %if.then108.i, %land.lhs.true103.i, %land.lhs.true.i, %while.end.i, %while.body.i188
%aFreq.1.i = phi i32 [ %aFreq.0518.i, %if.then108.i ], [ %add93.i, %land.lhs.true103.i ], [ %add93.i, %land.lhs.true.i ], [ %add93.i, %while.end.i ], [ 0, %while.body.i188 ]
%ge.1.i = phi i32 [ 0, %if.then108.i ], [ %inc87.i, %land.lhs.true103.i ], [ %inc87.i, %land.lhs.true.i ], [ %inc87.i, %while.end.i ], [ 0, %while.body.i188 ]
br i1 undef, label %if.then122.i, label %for.cond138.preheader.i
if.then122.i: ; preds = %if.end117.i
call void (...)* @fprintf(i32 undef, i32 %gs.0526.i, i32 %ge.1.i, i32 %aFreq.1.i, double undef) nounwind
br label %for.cond138.preheader.i
for.cond138.preheader.i: ; preds = %if.then122.i, %if.end117.i
br i1 undef, label %for.body143.lr.ph.i, label %for.end173.i
for.body143.lr.ph.i: ; preds = %for.cond138.preheader.i
br label %for.body143.i
for.body143.i: ; preds = %for.body143.i, %for.body143.lr.ph.i
br i1 undef, label %for.end173.i, label %for.body143.i
for.end173.i: ; preds = %for.body143.i, %for.cond138.preheader.i
%add177.i = add nsw i32 %ge.1.i, 1
%cmp73.i = icmp sgt i32 undef, 0
br i1 %cmp73.i, label %while.body.i188, label %for.cond182.preheader.i
for.inc220.us.i: ; preds = %for.cond182.preheader.i
unreachable
while.body300.preheader.i: ; preds = %for.cond182.preheader.i
br i1 undef, label %for.end335.i, label %while.end2742.i
for.end335.i: ; preds = %for.end2039.i, %while.body300.preheader.i
br label %for.body2021.i
for.body2021.i: ; preds = %for.body2021.i, %for.end335.i
br i1 undef, label %for.body2021.i, label %for.end2039.i
for.end2039.i: ; preds = %for.body2021.i
br label %for.end335.i
while.end2742.i: ; preds = %while.body300.preheader.i
br i1 undef, label %if.then2748.i, label %for.body2778.i
if.then2748.i: ; preds = %while.end2742.i
unreachable
for.body2778.i: ; preds = %while.end2742.i
unreachable
for.inc27.us.5.i: ; preds = %if.end.i
br label %for.end30.i
if.end85: ; preds = %entry
ret void
}
declare void @fprintf(...) nounwind