llvm/test/CodeGen/X86/misched-balance.ll
Will Dietz e4b44c1617 MachineSink: Fix and tweak critical-edge breaking heuristic.
Per original comment, the intention of this loop
is to go ahead and break the critical edge
(in order to sink this instruction) if there's
reason to believe doing so might "unblock" the
sinking of additional instructions that define
registers used by this one.  The idea is that if
we have a few instructions to sink "together"
breaking the edge might be worthwhile.

This commit makes a few small changes
to help better realize this goal:

First, modify the loop to ignore registers
defined by this instruction.  We don't
sink definitions of physical registers,
and sinking an SSA definition isn't
going to unblock an upstream instruction.

Second, ignore uses of physical registers.
Instructions that define physical registers are
rejected for sinking, and so moving this one
won't enable moving any defining instructions.
As an added bonus, while virtual register
use-def chains are generally small due
to SSA goodness, iteration over the uses
and definitions (used by hasOneNonDBGUse)
for physical registers like EFLAGS
can be rather expensive in practice.
(This is the original reason for looking at this)

Finally, to keep things simple continue
to only consider this trick for registers that
have a single use (via hasOneNonDBGUse),
but to avoid spuriously breaking critical edges
only do so if the definition resides
in the same MBB and therefore this one directly
blocks it from being sunk as well.
If sinking them together is meant to be,
let the iterative nature of this pass
sink the definition into this block first.

Update tests to accomodate this change,
add new testcase where sinking avoids pipeline stalls.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192608 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-14 16:57:17 +00:00

278 lines
11 KiB
LLVM

; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -mcpu=core2 -pre-RA-sched=source -enable-misched -verify-machineinstrs | FileCheck %s
;
; Verify that misched resource/latency balancy heuristics are sane.
define void @unrolled_mmult1(i32* %tmp55, i32* %tmp56, i32* %pre, i32* %pre94,
i32* %pre95, i32* %pre96, i32* %pre97, i32* %pre98, i32* %pre99,
i32* %pre100, i32* %pre101, i32* %pre102, i32* %pre103, i32* %pre104)
nounwind uwtable ssp {
entry:
br label %for.body
; imull folded loads should be in order and interleaved with addl, never
; adjacent. Also check that we have no spilling.
;
; Since mmult1 IR is already in good order, this effectively ensure
; the scheduler maintains source order.
;
; CHECK-LABEL: %for.body
; CHECK-NOT: %rsp
; CHECK: imull 4
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK: imull 8
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK: imull 12
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK: imull 16
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK: imull 20
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK: imull 24
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK: imull 28
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK: imull 32
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK: imull 36
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK-NOT: {{imull|rsp}}
; CHECK-LABEL: %end
for.body:
%indvars.iv42.i = phi i64 [ %indvars.iv.next43.i, %for.body ], [ 0, %entry ]
%tmp57 = load i32* %tmp56, align 4
%arrayidx12.us.i61 = getelementptr inbounds i32* %pre, i64 %indvars.iv42.i
%tmp58 = load i32* %arrayidx12.us.i61, align 4
%mul.us.i = mul nsw i32 %tmp58, %tmp57
%arrayidx8.us.i.1 = getelementptr inbounds i32* %tmp56, i64 1
%tmp59 = load i32* %arrayidx8.us.i.1, align 4
%arrayidx12.us.i61.1 = getelementptr inbounds i32* %pre94, i64 %indvars.iv42.i
%tmp60 = load i32* %arrayidx12.us.i61.1, align 4
%mul.us.i.1 = mul nsw i32 %tmp60, %tmp59
%add.us.i.1 = add nsw i32 %mul.us.i.1, %mul.us.i
%arrayidx8.us.i.2 = getelementptr inbounds i32* %tmp56, i64 2
%tmp61 = load i32* %arrayidx8.us.i.2, align 4
%arrayidx12.us.i61.2 = getelementptr inbounds i32* %pre95, i64 %indvars.iv42.i
%tmp62 = load i32* %arrayidx12.us.i61.2, align 4
%mul.us.i.2 = mul nsw i32 %tmp62, %tmp61
%add.us.i.2 = add nsw i32 %mul.us.i.2, %add.us.i.1
%arrayidx8.us.i.3 = getelementptr inbounds i32* %tmp56, i64 3
%tmp63 = load i32* %arrayidx8.us.i.3, align 4
%arrayidx12.us.i61.3 = getelementptr inbounds i32* %pre96, i64 %indvars.iv42.i
%tmp64 = load i32* %arrayidx12.us.i61.3, align 4
%mul.us.i.3 = mul nsw i32 %tmp64, %tmp63
%add.us.i.3 = add nsw i32 %mul.us.i.3, %add.us.i.2
%arrayidx8.us.i.4 = getelementptr inbounds i32* %tmp56, i64 4
%tmp65 = load i32* %arrayidx8.us.i.4, align 4
%arrayidx12.us.i61.4 = getelementptr inbounds i32* %pre97, i64 %indvars.iv42.i
%tmp66 = load i32* %arrayidx12.us.i61.4, align 4
%mul.us.i.4 = mul nsw i32 %tmp66, %tmp65
%add.us.i.4 = add nsw i32 %mul.us.i.4, %add.us.i.3
%arrayidx8.us.i.5 = getelementptr inbounds i32* %tmp56, i64 5
%tmp67 = load i32* %arrayidx8.us.i.5, align 4
%arrayidx12.us.i61.5 = getelementptr inbounds i32* %pre98, i64 %indvars.iv42.i
%tmp68 = load i32* %arrayidx12.us.i61.5, align 4
%mul.us.i.5 = mul nsw i32 %tmp68, %tmp67
%add.us.i.5 = add nsw i32 %mul.us.i.5, %add.us.i.4
%arrayidx8.us.i.6 = getelementptr inbounds i32* %tmp56, i64 6
%tmp69 = load i32* %arrayidx8.us.i.6, align 4
%arrayidx12.us.i61.6 = getelementptr inbounds i32* %pre99, i64 %indvars.iv42.i
%tmp70 = load i32* %arrayidx12.us.i61.6, align 4
%mul.us.i.6 = mul nsw i32 %tmp70, %tmp69
%add.us.i.6 = add nsw i32 %mul.us.i.6, %add.us.i.5
%arrayidx8.us.i.7 = getelementptr inbounds i32* %tmp56, i64 7
%tmp71 = load i32* %arrayidx8.us.i.7, align 4
%arrayidx12.us.i61.7 = getelementptr inbounds i32* %pre100, i64 %indvars.iv42.i
%tmp72 = load i32* %arrayidx12.us.i61.7, align 4
%mul.us.i.7 = mul nsw i32 %tmp72, %tmp71
%add.us.i.7 = add nsw i32 %mul.us.i.7, %add.us.i.6
%arrayidx8.us.i.8 = getelementptr inbounds i32* %tmp56, i64 8
%tmp73 = load i32* %arrayidx8.us.i.8, align 4
%arrayidx12.us.i61.8 = getelementptr inbounds i32* %pre101, i64 %indvars.iv42.i
%tmp74 = load i32* %arrayidx12.us.i61.8, align 4
%mul.us.i.8 = mul nsw i32 %tmp74, %tmp73
%add.us.i.8 = add nsw i32 %mul.us.i.8, %add.us.i.7
%arrayidx8.us.i.9 = getelementptr inbounds i32* %tmp56, i64 9
%tmp75 = load i32* %arrayidx8.us.i.9, align 4
%arrayidx12.us.i61.9 = getelementptr inbounds i32* %pre102, i64 %indvars.iv42.i
%tmp76 = load i32* %arrayidx12.us.i61.9, align 4
%mul.us.i.9 = mul nsw i32 %tmp76, %tmp75
%add.us.i.9 = add nsw i32 %mul.us.i.9, %add.us.i.8
%arrayidx16.us.i = getelementptr inbounds i32* %tmp55, i64 %indvars.iv42.i
store i32 %add.us.i.9, i32* %arrayidx16.us.i, align 4
%indvars.iv.next43.i = add i64 %indvars.iv42.i, 1
%lftr.wideiv = trunc i64 %indvars.iv.next43.i to i32
%exitcond = icmp eq i32 %lftr.wideiv, 10
br i1 %exitcond, label %end, label %for.body
end:
ret void
}
; Unlike the above loop, this IR starts out bad and must be
; rescheduled.
;
; CHECK-LABEL: %for.body
; CHECK-NOT: %rsp
; CHECK: imull 4
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK: imull 8
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK: imull 12
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK: imull 16
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK: imull 20
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK: imull 24
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK: imull 28
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK: imull 32
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK: imull 36
; CHECK-NOT: {{imull|rsp}}
; CHECK: addl
; CHECK-NOT: {{imull|rsp}}
; CHECK-LABEL: %end
define void @unrolled_mmult2(i32* %tmp55, i32* %tmp56, i32* %pre, i32* %pre94,
i32* %pre95, i32* %pre96, i32* %pre97, i32* %pre98, i32* %pre99,
i32* %pre100, i32* %pre101, i32* %pre102, i32* %pre103, i32* %pre104)
nounwind uwtable ssp {
entry:
br label %for.body
for.body:
%indvars.iv42.i = phi i64 [ %indvars.iv.next43.i, %for.body ], [ 0, %entry ]
%tmp57 = load i32* %tmp56, align 4
%arrayidx12.us.i61 = getelementptr inbounds i32* %pre, i64 %indvars.iv42.i
%tmp58 = load i32* %arrayidx12.us.i61, align 4
%arrayidx8.us.i.1 = getelementptr inbounds i32* %tmp56, i64 1
%tmp59 = load i32* %arrayidx8.us.i.1, align 4
%arrayidx12.us.i61.1 = getelementptr inbounds i32* %pre94, i64 %indvars.iv42.i
%tmp60 = load i32* %arrayidx12.us.i61.1, align 4
%arrayidx8.us.i.2 = getelementptr inbounds i32* %tmp56, i64 2
%tmp61 = load i32* %arrayidx8.us.i.2, align 4
%arrayidx12.us.i61.2 = getelementptr inbounds i32* %pre95, i64 %indvars.iv42.i
%tmp62 = load i32* %arrayidx12.us.i61.2, align 4
%arrayidx8.us.i.3 = getelementptr inbounds i32* %tmp56, i64 3
%tmp63 = load i32* %arrayidx8.us.i.3, align 4
%arrayidx12.us.i61.3 = getelementptr inbounds i32* %pre96, i64 %indvars.iv42.i
%tmp64 = load i32* %arrayidx12.us.i61.3, align 4
%arrayidx8.us.i.4 = getelementptr inbounds i32* %tmp56, i64 4
%tmp65 = load i32* %arrayidx8.us.i.4, align 4
%arrayidx12.us.i61.4 = getelementptr inbounds i32* %pre97, i64 %indvars.iv42.i
%tmp66 = load i32* %arrayidx12.us.i61.4, align 4
%arrayidx8.us.i.5 = getelementptr inbounds i32* %tmp56, i64 5
%tmp67 = load i32* %arrayidx8.us.i.5, align 4
%arrayidx12.us.i61.5 = getelementptr inbounds i32* %pre98, i64 %indvars.iv42.i
%tmp68 = load i32* %arrayidx12.us.i61.5, align 4
%arrayidx8.us.i.6 = getelementptr inbounds i32* %tmp56, i64 6
%tmp69 = load i32* %arrayidx8.us.i.6, align 4
%arrayidx12.us.i61.6 = getelementptr inbounds i32* %pre99, i64 %indvars.iv42.i
%tmp70 = load i32* %arrayidx12.us.i61.6, align 4
%mul.us.i = mul nsw i32 %tmp58, %tmp57
%arrayidx8.us.i.7 = getelementptr inbounds i32* %tmp56, i64 7
%tmp71 = load i32* %arrayidx8.us.i.7, align 4
%arrayidx12.us.i61.7 = getelementptr inbounds i32* %pre100, i64 %indvars.iv42.i
%tmp72 = load i32* %arrayidx12.us.i61.7, align 4
%arrayidx8.us.i.8 = getelementptr inbounds i32* %tmp56, i64 8
%tmp73 = load i32* %arrayidx8.us.i.8, align 4
%arrayidx12.us.i61.8 = getelementptr inbounds i32* %pre101, i64 %indvars.iv42.i
%tmp74 = load i32* %arrayidx12.us.i61.8, align 4
%arrayidx8.us.i.9 = getelementptr inbounds i32* %tmp56, i64 9
%tmp75 = load i32* %arrayidx8.us.i.9, align 4
%arrayidx12.us.i61.9 = getelementptr inbounds i32* %pre102, i64 %indvars.iv42.i
%tmp76 = load i32* %arrayidx12.us.i61.9, align 4
%mul.us.i.1 = mul nsw i32 %tmp60, %tmp59
%add.us.i.1 = add nsw i32 %mul.us.i.1, %mul.us.i
%mul.us.i.2 = mul nsw i32 %tmp62, %tmp61
%add.us.i.2 = add nsw i32 %mul.us.i.2, %add.us.i.1
%mul.us.i.3 = mul nsw i32 %tmp64, %tmp63
%add.us.i.3 = add nsw i32 %mul.us.i.3, %add.us.i.2
%mul.us.i.4 = mul nsw i32 %tmp66, %tmp65
%add.us.i.4 = add nsw i32 %mul.us.i.4, %add.us.i.3
%mul.us.i.5 = mul nsw i32 %tmp68, %tmp67
%add.us.i.5 = add nsw i32 %mul.us.i.5, %add.us.i.4
%mul.us.i.6 = mul nsw i32 %tmp70, %tmp69
%add.us.i.6 = add nsw i32 %mul.us.i.6, %add.us.i.5
%mul.us.i.7 = mul nsw i32 %tmp72, %tmp71
%add.us.i.7 = add nsw i32 %mul.us.i.7, %add.us.i.6
%mul.us.i.8 = mul nsw i32 %tmp74, %tmp73
%add.us.i.8 = add nsw i32 %mul.us.i.8, %add.us.i.7
%mul.us.i.9 = mul nsw i32 %tmp76, %tmp75
%add.us.i.9 = add nsw i32 %mul.us.i.9, %add.us.i.8
%arrayidx16.us.i = getelementptr inbounds i32* %tmp55, i64 %indvars.iv42.i
store i32 %add.us.i.9, i32* %arrayidx16.us.i, align 4
%indvars.iv.next43.i = add i64 %indvars.iv42.i, 1
%lftr.wideiv = trunc i64 %indvars.iv.next43.i to i32
%exitcond = icmp eq i32 %lftr.wideiv, 10
br i1 %exitcond, label %end, label %for.body
end:
ret void
}
; A mildly interesting little block extracted from a cipher. The
; balanced heuristics are interesting here because we have resource,
; latency, and register limits all at once. For now, simply check that
; we don't use any callee-saves.
; CHECK-LABEL: @encpc1
; CHECK-LABEL: %entry
; CHECK-NOT: push
; CHECK-NOT: pop
; CHECK: ret
@a = external global i32, align 4
@b = external global i32, align 4
@c = external global i32, align 4
@d = external global i32, align 4
define i32 @encpc1() nounwind {
entry:
%l1 = load i32* @a, align 16
%conv = shl i32 %l1, 8
%s5 = lshr i32 %l1, 8
%add = or i32 %conv, %s5
store i32 %add, i32* @b
%l6 = load i32* @a
%l7 = load i32* @c
%add.i = add i32 %l7, %l6
%idxprom.i = zext i32 %l7 to i64
%arrayidx.i = getelementptr inbounds i32* @d, i64 %idxprom.i
%l8 = load i32* %arrayidx.i
store i32 346, i32* @c
store i32 20021, i32* @d
%l9 = load i32* @a
store i32 %l8, i32* @a
store i32 %l9, i32* @b
store i32 %add.i, i32* @c
store i32 %l9, i32* @d
%cmp.i = icmp eq i32 %add.i, 0
%s10 = lshr i32 %l1, 16
%s12 = lshr i32 %l1, 24
%s14 = lshr i32 %l1, 30
br i1 %cmp.i, label %if, label %return
if:
%sa = add i32 %s5, %s10
%sb = add i32 %sa, %s12
%sc = add i32 %sb, %s14
br label %return
return:
%result = phi i32 [0, %entry], [%sc, %if]
ret i32 %result
}