Last of the major pieces to NewGVN - yay!

Summary:
NewGVN: Handle equivalence between phi of ops and op of phis.

This makes our GVN mostly-complete. It would be complete, modulo some
deliberate choices we make.  This means it detects roughly all herband
equivalences in polynomial time, including cases notoriously hard for
other GVN's to detect.  It also detects a very large swath of the
cases we currently rely on instcombine to detect that involve folding
upwards through phis.

Fixes PR 31125, 31463, PR 31868

Reviewers: davide

Subscribers: Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D32151

llvm-svn: 303444
This commit is contained in:
Daniel Berlin 2017-05-19 19:01:27 +00:00
parent ff15200b1d
commit b527b2cf13
3 changed files with 950 additions and 127 deletions

File diff suppressed because it is too large Load Diff

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@ -0,0 +1,415 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -basicaa -newgvn -S | FileCheck %s
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
define i32 @test1(i32, i8**) {
; CHECK-LABEL: @test1(
; CHECK-NEXT: [[TMP3:%.*]] = icmp ne i32 [[TMP0:%.*]], 0
; CHECK-NEXT: br i1 [[TMP3]], label [[TMP4:%.*]], label [[TMP5:%.*]]
; CHECK: br label [[TMP6:%.*]]
; CHECK: br label [[TMP6]]
; CHECK: [[TMP7:%.*]] = phi i32 [ 75, [[TMP4]] ], [ 105, [[TMP5]] ]
; CHECK-NEXT: [[DOT0:%.*]] = phi i32 [ 5, [[TMP4]] ], [ 7, [[TMP5]] ]
; CHECK-NEXT: ret i32 [[TMP7]]
;
%3 = icmp ne i32 %0, 0
br i1 %3, label %4, label %5
; <label>:4: ; preds = %2
br label %6
; <label>:5: ; preds = %2
br label %6
; <label>:6: ; preds = %5, %4
%.0 = phi i32 [ 5, %4 ], [ 7, %5 ]
%7 = mul nsw i32 %.0, 15
ret i32 %7
}
define i32 @test2(i32) {
; CHECK-LABEL: @test2(
; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i32 [[TMP0:%.*]], 0
; CHECK-NEXT: br i1 [[TMP2]], label [[TMP3:%.*]], label [[TMP4:%.*]]
; CHECK: br label [[TMP5:%.*]]
; CHECK: br label [[TMP5]]
; CHECK: [[DOT01:%.*]] = phi i32 [ 3, [[TMP3]] ], [ 2, [[TMP4]] ]
; CHECK-NEXT: [[DOT0:%.*]] = phi i32 [ 2, [[TMP3]] ], [ 3, [[TMP4]] ]
; CHECK-NEXT: ret i32 5
;
%2 = icmp ne i32 %0, 0
br i1 %2, label %3, label %4
; <label>:3: ; preds = %1
br label %5
; <label>:4: ; preds = %1
br label %5
; <label>:5: ; preds = %4, %3
%.01 = phi i32 [ 3, %3 ], [ 2, %4 ]
%.0 = phi i32 [ 2, %3 ], [ 3, %4 ]
%6 = add nsw i32 %.01, %.0
ret i32 %6
}
define i32 @test3(i1 %which) {
; CHECK-LABEL: @test3(
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 [[WHICH:%.*]], label [[FINAL:%.*]], label [[DELAY:%.*]]
; CHECK: delay:
; CHECK-NEXT: br label [[FINAL]]
; CHECK: final:
; CHECK-NEXT: [[TMP0:%.*]] = phi i32 [ -877, [[ENTRY:%.*]] ], [ 113, [[DELAY]] ]
; CHECK-NEXT: [[A:%.*]] = phi i32 [ 1000, [[ENTRY]] ], [ 10, [[DELAY]] ]
; CHECK-NEXT: ret i32 [[TMP0]]
;
entry:
br i1 %which, label %final, label %delay
delay:
br label %final
final:
%A = phi i32 [ 1000, %entry ], [ 10, %delay ]
%value = sub i32 123, %A
ret i32 %value
}
define <2 x i32> @test3vec(i1 %which) {
; CHECK-LABEL: @test3vec(
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 [[WHICH:%.*]], label [[FINAL:%.*]], label [[DELAY:%.*]]
; CHECK: delay:
; CHECK-NEXT: br label [[FINAL]]
; CHECK: final:
; CHECK-NEXT: [[TMP0:%.*]] = phi <2 x i32> [ <i32 -877, i32 -877>, [[ENTRY:%.*]] ], [ <i32 113, i32 113>, [[DELAY]] ]
; CHECK-NEXT: [[A:%.*]] = phi <2 x i32> [ <i32 1000, i32 1000>, [[ENTRY]] ], [ <i32 10, i32 10>, [[DELAY]] ]
; CHECK-NEXT: ret <2 x i32> [[TMP0]]
;
entry:
br i1 %which, label %final, label %delay
delay:
br label %final
final:
%A = phi <2 x i32> [ <i32 1000, i32 1000>, %entry ], [ <i32 10, i32 10>, %delay ]
%value = sub <2 x i32> <i32 123, i32 123>, %A
ret <2 x i32> %value
}
define <2 x i32> @test3vec2(i1 %which) {
; CHECK-LABEL: @test3vec2(
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 [[WHICH:%.*]], label [[FINAL:%.*]], label [[DELAY:%.*]]
; CHECK: delay:
; CHECK-NEXT: br label [[FINAL]]
; CHECK: final:
; CHECK-NEXT: [[TMP0:%.*]] = phi <2 x i32> [ <i32 -877, i32 -2167>, [[ENTRY:%.*]] ], [ <i32 113, i32 303>, [[DELAY]] ]
; CHECK-NEXT: [[A:%.*]] = phi <2 x i32> [ <i32 1000, i32 2500>, [[ENTRY]] ], [ <i32 10, i32 30>, [[DELAY]] ]
; CHECK-NEXT: ret <2 x i32> [[TMP0]]
;
entry:
br i1 %which, label %final, label %delay
delay:
br label %final
final:
%A = phi <2 x i32> [ <i32 1000, i32 2500>, %entry ], [ <i32 10, i32 30>, %delay ]
%value = sub <2 x i32> <i32 123, i32 333>, %A
ret <2 x i32> %value
}
;; This example is a bit contrived because we can't create fake memoryuses, so we use two loads in the if blocks
define i32 @test4(i32, i8**, i32* noalias, i32* noalias) {
; CHECK-LABEL: @test4(
; CHECK-NEXT: store i32 5, i32* [[TMP2:%.*]], align 4
; CHECK-NEXT: store i32 7, i32* [[TMP3:%.*]], align 4
; CHECK-NEXT: [[TMP5:%.*]] = icmp ne i32 [[TMP0:%.*]], 0
; CHECK-NEXT: br i1 [[TMP5]], label [[TMP6:%.*]], label [[TMP7:%.*]]
; CHECK: br label [[TMP8:%.*]]
; CHECK: br label [[TMP8]]
; CHECK: [[DOT01:%.*]] = phi i32 [ 5, [[TMP6]] ], [ 7, [[TMP7]] ]
; CHECK-NEXT: [[DOT0:%.*]] = phi i32* [ [[TMP2]], [[TMP6]] ], [ [[TMP3]], [[TMP7]] ]
; CHECK-NEXT: [[TMP9:%.*]] = load i32, i32* [[DOT0]], align 4
; CHECK-NEXT: [[TMP10:%.*]] = mul nsw i32 [[TMP9]], 15
; CHECK-NEXT: [[TMP11:%.*]] = mul nsw i32 [[TMP10]], [[DOT01]]
; CHECK-NEXT: ret i32 [[TMP11]]
;
store i32 5, i32* %2, align 4
store i32 7, i32* %3, align 4
%5 = icmp ne i32 %0, 0
br i1 %5, label %6, label %8
; <label>:6: ; preds = %4
%7 = load i32, i32* %2, align 4
br label %10
; <label>:8: ; preds = %4
%9 = load i32, i32* %3, align 4
br label %10
; <label>:10: ; preds = %8, %6
%.01 = phi i32 [ %7, %6 ], [ %9, %8 ]
%.0 = phi i32* [ %2, %6 ], [ %3, %8 ]
%11 = load i32, i32* %.0, align 4
%12 = mul nsw i32 %11, 15
%13 = mul nsw i32 %12, %.01
ret i32 %13
}
@global = common global [100 x i64] zeroinitializer, align 16
@global.1 = common global [100 x i64] zeroinitializer, align 16
define i64 @test5(i64 %arg) {
; CHECK-LABEL: @test5(
; CHECK-NEXT: bb:
; CHECK-NEXT: [[TMP:%.*]] = alloca i64, align 8
; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i64 [[ARG:%.*]], 0
; CHECK-NEXT: br i1 [[TMP1]], label [[BB28:%.*]], label [[BB2:%.*]]
; CHECK: bb2:
; CHECK-NEXT: br label [[BB7:%.*]]
; CHECK: bb4:
; CHECK-NEXT: br label [[BB5:%.*]]
; CHECK: bb5:
; CHECK-NEXT: [[TMP6:%.*]] = icmp eq i64 [[TMP9:%.*]], 0
; CHECK-NEXT: br i1 [[TMP6]], label [[BB27:%.*]], label [[BB7]]
; CHECK: bb7:
; CHECK-NEXT: [[TMP8:%.*]] = phi i64 [ [[ARG]], [[BB2]] ], [ [[TMP9]], [[BB5]] ]
; CHECK-NEXT: [[TMP9]] = add nsw i64 [[TMP8]], -1
; CHECK-NEXT: [[TMP10:%.*]] = load i64, i64* getelementptr inbounds ([100 x i64], [100 x i64]* @global, i64 0, i64 0), align 16
; CHECK-NEXT: [[TMP11:%.*]] = load i64, i64* getelementptr inbounds ([100 x i64], [100 x i64]* @global.1, i64 0, i64 0), align 16
; CHECK-NEXT: [[TMP12:%.*]] = mul nsw i64 [[TMP11]], [[TMP10]]
; CHECK-NEXT: [[TMP13:%.*]] = icmp eq i64 [[TMP12]], 0
; CHECK-NEXT: br i1 [[TMP13]], label [[BB5]], label [[BB14:%.*]]
; CHECK: bb14:
; CHECK-NEXT: br label [[BB15:%.*]]
; CHECK: bb15:
; CHECK-NEXT: [[TMP0:%.*]] = phi i64 [ [[TMP25:%.*]], [[BB15]] ], [ [[TMP12]], [[BB14]] ]
; CHECK-NEXT: [[TMP16:%.*]] = phi i64 [ [[TMP24:%.*]], [[BB15]] ], [ [[TMP11]], [[BB14]] ]
; CHECK-NEXT: [[TMP17:%.*]] = phi i64 [ [[TMP22:%.*]], [[BB15]] ], [ [[TMP10]], [[BB14]] ]
; CHECK-NEXT: [[TMP18:%.*]] = phi i64 [ [[TMP20:%.*]], [[BB15]] ], [ 0, [[BB14]] ]
; CHECK-NEXT: store i64 [[TMP0]], i64* [[TMP]], align 8
; CHECK-NEXT: [[TMP20]] = add nuw nsw i64 [[TMP18]], 1
; CHECK-NEXT: [[TMP21:%.*]] = getelementptr inbounds [100 x i64], [100 x i64]* @global, i64 0, i64 [[TMP20]]
; CHECK-NEXT: [[TMP22]] = load i64, i64* [[TMP21]], align 8
; CHECK-NEXT: [[TMP23:%.*]] = getelementptr inbounds [100 x i64], [100 x i64]* @global.1, i64 0, i64 [[TMP20]]
; CHECK-NEXT: [[TMP24]] = load i64, i64* [[TMP23]], align 8
; CHECK-NEXT: [[TMP25]] = mul nsw i64 [[TMP24]], [[TMP22]]
; CHECK-NEXT: [[TMP26:%.*]] = icmp eq i64 [[TMP20]], [[TMP25]]
; CHECK-NEXT: br i1 [[TMP26]], label [[BB4:%.*]], label [[BB15]]
; CHECK: bb27:
; CHECK-NEXT: br label [[BB28]]
; CHECK: bb28:
; CHECK-NEXT: ret i64 0
;
bb:
%tmp = alloca i64, align 8
%tmp1 = icmp eq i64 %arg, 0
br i1 %tmp1, label %bb28, label %bb2
bb2: ; preds = %bb
%tmp3 = bitcast i64* %tmp to i8*
br label %bb7
bb4: ; preds = %bb15
br label %bb5
bb5: ; preds = %bb7, %bb4
%tmp6 = icmp eq i64 %tmp9, 0
br i1 %tmp6, label %bb27, label %bb7
bb7: ; preds = %bb5, %bb2
%tmp8 = phi i64 [ %arg, %bb2 ], [ %tmp9, %bb5 ]
%tmp9 = add nsw i64 %tmp8, -1
%tmp10 = load i64, i64* getelementptr inbounds ([100 x i64], [100 x i64]* @global, i64 0, i64 0), align 16
%tmp11 = load i64, i64* getelementptr inbounds ([100 x i64], [100 x i64]* @global.1, i64 0, i64 0), align 16
%tmp12 = mul nsw i64 %tmp11, %tmp10
%tmp13 = icmp eq i64 %tmp12, 0
br i1 %tmp13, label %bb5, label %bb14
bb14: ; preds = %bb7
br label %bb15
bb15: ; preds = %bb15, %bb14
%tmp16 = phi i64 [ %tmp24, %bb15 ], [ %tmp11, %bb14 ]
%tmp17 = phi i64 [ %tmp22, %bb15 ], [ %tmp10, %bb14 ]
%tmp18 = phi i64 [ %tmp20, %bb15 ], [ 0, %bb14 ]
;; This multiply is an op of phis which is really equivalent to phi(tmp25, tmp12)
%tmp19 = mul nsw i64 %tmp16, %tmp17
store i64 %tmp19, i64* %tmp, align 8
%tmp20 = add nuw nsw i64 %tmp18, 1
%tmp21 = getelementptr inbounds [100 x i64], [100 x i64]* @global, i64 0, i64 %tmp20
%tmp22 = load i64, i64* %tmp21, align 8
%tmp23 = getelementptr inbounds [100 x i64], [100 x i64]* @global.1, i64 0, i64 %tmp20
%tmp24 = load i64, i64* %tmp23, align 8
%tmp25 = mul nsw i64 %tmp24, %tmp22
%tmp26 = icmp eq i64 %tmp20, %tmp25
br i1 %tmp26, label %bb4, label %bb15
bb27: ; preds = %bb5
br label %bb28
bb28: ; preds = %bb27, %bb
ret i64 0
}
;; These icmps are all equivalent to phis of constants
define i8 @test6(i8* %addr) {
; CHECK-LABEL: @test6(
; CHECK-NEXT: entry-block:
; CHECK-NEXT: br label %main-loop
; CHECK: main-loop:
; CHECK-NEXT: [[TMP0:%.*]] = phi i1 [ true, %entry-block ], [ false, [[CORE:%.*]] ]
; CHECK-NEXT: [[TMP1:%.*]] = phi i1 [ false, %entry-block ], [ true, [[CORE]] ]
; CHECK-NEXT: [[PHI:%.*]] = phi i8 [ 0, %entry-block ], [ 1, [[CORE]] ]
; CHECK-NEXT: store volatile i8 0, i8* [[ADDR:%.*]]
; CHECK-NEXT: br i1 [[TMP0]], label %busy-wait-phi-0, label [[EXIT:%.*]]
; CHECK: busy-wait-phi-0:
; CHECK-NEXT: [[LOAD:%.*]] = load volatile i8, i8* [[ADDR]]
; CHECK-NEXT: [[ICMP:%.*]] = icmp eq i8 [[LOAD]], 0
; CHECK-NEXT: br i1 [[ICMP]], label %busy-wait-phi-0, label [[CORE]]
; CHECK: core:
; CHECK-NEXT: br i1 [[TMP1]], label [[TRAP:%.*]], label %main-loop
; CHECK: trap:
; CHECK-NEXT: ret i8 1
; CHECK: exit:
; CHECK-NEXT: ret i8 0
;
entry-block:
br label %main-loop
main-loop:
%phi = phi i8 [ 0, %entry-block ], [ 1, %core ]
%switch_0 = icmp eq i8 %phi, 0
store volatile i8 0, i8* %addr
br i1 %switch_0, label %busy-wait-phi-0, label %exit
busy-wait-phi-0:
%load = load volatile i8, i8* %addr
%icmp = icmp eq i8 %load, 0
br i1 %icmp, label %busy-wait-phi-0, label %core
core:
%switch_1 = icmp eq i8 %phi, 1
br i1 %switch_1, label %trap, label %main-loop
trap:
ret i8 1
exit:
ret i8 0
}
; Test that we don't infinite loop simplifying
; an undefined value that can go both ways.
define void @test7() {
; CHECK-LABEL: @test7(
; CHECK-NEXT: bb:
; CHECK-NEXT: br label [[BB1:%.*]]
; CHECK: bb1:
; CHECK-NEXT: br label [[BB1]]
;
bb:
br label %bb1
bb1: ; preds = %bb1, %bb
%tmp = phi i32 [ undef, %bb ], [ %tmp3, %bb1 ]
%tmp2 = icmp eq i32 %tmp, 0
%tmp3 = select i1 %tmp2, i32 1, i32 %tmp
br label %bb1
}
; Test that we get a consistent answer about what the
; value of this undefined select is.
define void @test8() {
; CHECK-LABEL: @test8(
; CHECK-NEXT: bb:
; CHECK-NEXT: br label [[BB1:%.*]]
; CHECK: bb1:
; CHECK-NEXT: br label [[BB1]]
;
bb:
%tmp = select i1 undef, i8 0, i8 1
br label %bb1
bb1: ; preds = %bb1, %bb
%tmp2 = phi i8 [ %tmp4, %bb1 ], [ %tmp, %bb ]
%tmp3 = icmp eq i8 %tmp2, 0
%tmp4 = select i1 %tmp3, i8 1, i8 %tmp2
br label %bb1
}
;; Make sure we handle the case where we later come up with an expression that we need
;; for a phi of ops.
define void @test9() {
; CHECK-LABEL: @test9(
; CHECK-NEXT: bb:
; CHECK-NEXT: br label [[BB1:%.*]]
; CHECK: bb1:
; CHECK-NEXT: br i1 undef, label [[BB1]], label [[BB2:%.*]]
; CHECK: bb2:
; CHECK-NEXT: br label [[BB6:%.*]]
; CHECK: bb6:
; CHECK-NEXT: [[TMP0:%.*]] = phi i32 [ -13, [[BB2]] ], [ [[TMP11:%.*]], [[BB6]] ]
; CHECK-NEXT: [[TMP7:%.*]] = phi i32 [ 1, [[BB2]] ], [ [[TMP8:%.*]], [[BB6]] ]
; CHECK-NEXT: [[TMP8]] = add nuw nsw i32 [[TMP7]], 1
; CHECK-NEXT: [[TMP11]] = add i32 -14, [[TMP8]]
; CHECK-NEXT: br label [[BB6]]
;
bb:
br label %bb1
bb1: ; preds = %bb1, %bb
br i1 undef, label %bb1, label %bb2
bb2: ; preds = %bb1
%tmp = select i1 true, i32 -14, i32 -10
%tmp3 = add i32 %tmp, 0
%tmp4 = select i1 true, i32 -14, i32 -10
%tmp5 = add i32 %tmp4, 0
br label %bb6
bb6: ; preds = %bb6, %bb2
%tmp7 = phi i32 [ 1, %bb2 ], [ %tmp13, %bb6 ]
%tmp8 = add nuw nsw i32 %tmp7, 1
%tmp9 = add i32 %tmp3, %tmp7
%tmp10 = select i1 false, i32 undef, i32 %tmp9
%tmp11 = add i32 %tmp5, %tmp8
%tmp12 = select i1 undef, i32 undef, i32 %tmp11
%tmp13 = add nuw nsw i32 %tmp7, 1
br label %bb6
}
;; Ensure that we revisit predicateinfo operands at the right points in time.
define void @test10() {
b:
%m = getelementptr i32, i32* null, i64 8
br label %g
g: ; preds = %i, %b
%n = phi i32* [ %h, %i ], [ null, %b ]
%h = getelementptr i32, i32* %n, i64 1
%j = icmp eq i32* %h, %m
br i1 %j, label %c, label %i
i: ; preds = %g
br i1 undef, label %k, label %g
k: ; preds = %i
%l = icmp eq i32* %n, %m
br i1 %l, label %c, label %o
o: ; preds = %k
br label %c
c: ; preds = %o, %k, %g
%0 = phi i32* [ undef, %o ], [ %m, %k ], [ %m, %g ]
ret void
}

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@ -13,11 +13,11 @@ define i32 @foo(i32*, i32) {
; CHECK-NEXT: [[TMP3:%.*]] = icmp ne i32 [[TMP1:%.*]], 0
; CHECK-NEXT: br i1 [[TMP3]], label [[TMP4:%.*]], label [[TMP5:%.*]]
; CHECK: br label [[TMP5]]
; CHECK: [[DOT0:%.*]] = phi i32 [ 10, [[TMP4]] ], [ 5, [[TMP2:%.*]] ]
; CHECK-NEXT: br i1 [[TMP3]], label [[TMP6:%.*]], label [[TMP8:%.*]]
; CHECK: [[TMP7:%.*]] = add nsw i32 [[DOT0]], 5
; CHECK-NEXT: br label [[TMP8]]
; CHECK: [[DOT1:%.*]] = phi i32 [ [[TMP7]], [[TMP6]] ], [ [[DOT0]], [[TMP5]] ]
; CHECK: [[TMP6:%.*]] = phi i32 [ 15, [[TMP4]] ], [ 10, [[TMP2:%.*]] ]
; CHECK-NEXT: [[DOT0:%.*]] = phi i32 [ 10, [[TMP4]] ], [ 5, [[TMP2]] ]
; CHECK-NEXT: br i1 [[TMP3]], label [[TMP7:%.*]], label [[TMP8:%.*]]
; CHECK: br label [[TMP8]]
; CHECK: [[DOT1:%.*]] = phi i32 [ [[TMP6]], [[TMP7]] ], [ [[DOT0]], [[TMP5]] ]
; CHECK-NEXT: ret i32 [[DOT1]]
;
store i32 5, i32* %0, align 4
@ -54,11 +54,11 @@ define i32 @foo2(i32*, i32) {
; CHECK-NEXT: br i1 [[TMP3]], label [[TMP4:%.*]], label [[TMP5:%.*]]
; CHECK: br label [[TMP6:%.*]]
; CHECK: br label [[TMP6]]
; CHECK: [[DOT0:%.*]] = phi i32 [ 10, [[TMP4]] ], [ 5, [[TMP5]] ]
; CHECK-NEXT: br i1 [[TMP3]], label [[TMP7:%.*]], label [[TMP9:%.*]]
; CHECK: [[TMP8:%.*]] = add nsw i32 [[DOT0]], 5
; CHECK-NEXT: br label [[TMP9]]
; CHECK: [[DOT1:%.*]] = phi i32 [ [[TMP8]], [[TMP7]] ], [ [[DOT0]], [[TMP6]] ]
; CHECK: [[TMP7:%.*]] = phi i32 [ 15, [[TMP4]] ], [ 10, [[TMP5]] ]
; CHECK-NEXT: [[DOT0:%.*]] = phi i32 [ 10, [[TMP4]] ], [ 5, [[TMP5]] ]
; CHECK-NEXT: br i1 [[TMP3]], label [[TMP8:%.*]], label [[TMP9:%.*]]
; CHECK: br label [[TMP9]]
; CHECK: [[DOT1:%.*]] = phi i32 [ [[TMP7]], [[TMP8]] ], [ [[DOT0]], [[TMP6]] ]
; CHECK-NEXT: ret i32 [[DOT1]]
;
store i32 5, i32* %0, align 4