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[MergeICmps] Add test for call before first load (NFC)
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If a clobbering call happens before all loads, that shouldn't
block the transform.
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@nikic
nikic committed Aug 26, 2021
1 parent 14d45e4 commit 8441a8e
Showing 1 changed file with 133 additions and 5 deletions.
138 changes: 133 additions & 5 deletions llvm/test/Transforms/MergeICmps/X86/split-block-does-work.ll
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Expand Up @@ -3,13 +3,13 @@

%S = type { i32, i32, i32, i32 }

declare void @foo(...) inaccessiblememonly
declare void @foo(...)

; We can split %entry and create a memcmp(16 bytes).
define zeroext i1 @opeq1(
; X86-LABEL: @opeq1(
; X86-NEXT: "entry+land.rhs.i+land.rhs.i.2+land.rhs.i.3":
; X86-NEXT: call void (...) @foo()
; X86-NEXT: call void (...) @foo() #[[ATTR2:[0-9]+]]
; X86-NEXT: [[TMP0:%.*]] = getelementptr inbounds [[S:%.*]], %S* [[A:%.*]], i64 0, i32 0
; X86-NEXT: [[TMP1:%.*]] = getelementptr inbounds [[S]], %S* [[B:%.*]], i64 0, i32 0
; X86-NEXT: [[CSTR:%.*]] = bitcast i32* [[TMP0]] to i8*
Expand All @@ -29,7 +29,7 @@ entry:
%first1.i = getelementptr inbounds %S, %S* %b, i64 0, i32 0
%1 = load i32, i32* %first1.i, align 4
; Does other work.
call void (...) @foo()
call void (...) @foo() inaccessiblememonly
%cmp.i = icmp eq i32 %0, %1
br i1 %cmp.i, label %land.rhs.i, label %opeq1.exit

Expand Down Expand Up @@ -71,7 +71,7 @@ define zeroext i1 @opeq1_discontiguous(
; X86-NEXT: [[TMP0:%.*]] = load i32, i32* [[FIRST_I]], align 4
; X86-NEXT: [[FIRST1_I:%.*]] = getelementptr inbounds [[S]], %S* [[B:%.*]], i64 0, i32 0
; X86-NEXT: [[TMP1:%.*]] = load i32, i32* [[FIRST1_I]], align 4
; X86-NEXT: call void (...) @foo()
; X86-NEXT: call void (...) @foo() #[[ATTR2]]
; X86-NEXT: [[CMP_I:%.*]] = icmp eq i32 [[TMP0]], [[TMP1]]
; X86-NEXT: br i1 [[CMP_I]], label [[LAND_RHS_I:%.*]], label [[OPEQ1_EXIT:%.*]]
; X86: land.rhs.i:
Expand Down Expand Up @@ -108,7 +108,7 @@ entry:
%first1.i = getelementptr inbounds %S, %S* %b, i64 0, i32 0
%1 = load i32, i32* %first1.i, align 4
; Does other work.
call void (...) @foo()
call void (...) @foo() inaccessiblememonly
%cmp.i = icmp eq i32 %0, %1
br i1 %cmp.i, label %land.rhs.i, label %opeq1.exit

Expand Down Expand Up @@ -140,3 +140,131 @@ opeq1.exit:
%8 = phi i1 [ false, %entry ], [ false, %land.rhs.i] , [ false, %land.rhs.i.2 ], [ %cmp4.i, %land.rhs.i.3 ]
ret i1 %8
}

; TODO: The call happen before the loads, so it cannot clobber them.
define zeroext i1 @opeq1_call_before_loads(
; X86-LABEL: @opeq1_call_before_loads(
; X86-NEXT: entry:
; X86-NEXT: call void (...) @foo()
; X86-NEXT: [[FIRST_I:%.*]] = getelementptr inbounds [[S:%.*]], %S* [[A:%.*]], i64 0, i32 0
; X86-NEXT: [[TMP0:%.*]] = load i32, i32* [[FIRST_I]], align 4
; X86-NEXT: [[FIRST1_I:%.*]] = getelementptr inbounds [[S]], %S* [[B:%.*]], i64 0, i32 0
; X86-NEXT: [[TMP1:%.*]] = load i32, i32* [[FIRST1_I]], align 4
; X86-NEXT: [[CMP_I:%.*]] = icmp eq i32 [[TMP0]], [[TMP1]]
; X86-NEXT: br i1 [[CMP_I]], label %"land.rhs.i+land.rhs.i.2+land.rhs.i.3", label [[OPEQ1_EXIT:%.*]]
; X86: "land.rhs.i+land.rhs.i.2+land.rhs.i.3":
; X86-NEXT: [[TMP2:%.*]] = getelementptr inbounds [[S]], %S* [[A]], i64 0, i32 1
; X86-NEXT: [[TMP3:%.*]] = getelementptr inbounds [[S]], %S* [[B]], i64 0, i32 1
; X86-NEXT: [[CSTR:%.*]] = bitcast i32* [[TMP2]] to i8*
; X86-NEXT: [[CSTR1:%.*]] = bitcast i32* [[TMP3]] to i8*
; X86-NEXT: [[MEMCMP:%.*]] = call i32 @memcmp(i8* [[CSTR]], i8* [[CSTR1]], i64 12)
; X86-NEXT: [[TMP4:%.*]] = icmp eq i32 [[MEMCMP]], 0
; X86-NEXT: br label [[OPEQ1_EXIT]]
; X86: opeq1.exit:
; X86-NEXT: [[TMP5:%.*]] = phi i1 [ false, [[ENTRY:%.*]] ], [ [[TMP4]], %"land.rhs.i+land.rhs.i.2+land.rhs.i.3" ]
; X86-NEXT: ret i1 [[TMP5]]
;
; Make sure this call is moved to the beginning of the entry block.
%S* nocapture readonly dereferenceable(16) %a,
%S* nocapture readonly dereferenceable(16) %b) local_unnamed_addr nofree nosync {
entry:
call void (...) @foo()
%first.i = getelementptr inbounds %S, %S* %a, i64 0, i32 0
%0 = load i32, i32* %first.i, align 4
%first1.i = getelementptr inbounds %S, %S* %b, i64 0, i32 0
%1 = load i32, i32* %first1.i, align 4
%cmp.i = icmp eq i32 %0, %1
br i1 %cmp.i, label %land.rhs.i, label %opeq1.exit

land.rhs.i:
%second.i = getelementptr inbounds %S, %S* %a, i64 0, i32 1
%2 = load i32, i32* %second.i, align 4
%second2.i = getelementptr inbounds %S, %S* %b, i64 0, i32 1
%3 = load i32, i32* %second2.i, align 4
%cmp2.i = icmp eq i32 %2, %3
br i1 %cmp2.i, label %land.rhs.i.2, label %opeq1.exit

land.rhs.i.2:
%third.i = getelementptr inbounds %S, %S* %a, i64 0, i32 2
%4 = load i32, i32* %third.i, align 4
%third2.i = getelementptr inbounds %S, %S* %b, i64 0, i32 2
%5 = load i32, i32* %third2.i, align 4
%cmp3.i = icmp eq i32 %4, %5
br i1 %cmp3.i, label %land.rhs.i.3, label %opeq1.exit

land.rhs.i.3:
%fourth.i = getelementptr inbounds %S, %S* %a, i64 0, i32 3
%6 = load i32, i32* %fourth.i, align 4
%fourth2.i = getelementptr inbounds %S, %S* %b, i64 0, i32 3
%7 = load i32, i32* %fourth2.i, align 4
%cmp4.i = icmp eq i32 %6, %7
br label %opeq1.exit

opeq1.exit:
%8 = phi i1 [ false, %entry ], [ false, %land.rhs.i] , [ false, %land.rhs.i.2 ], [ %cmp4.i, %land.rhs.i.3 ]
ret i1 %8
}

; Call happens after the loads, and may clobber them.
define zeroext i1 @opeq1_call_after_loads(
; X86-LABEL: @opeq1_call_after_loads(
; X86-NEXT: entry:
; X86-NEXT: [[FIRST_I:%.*]] = getelementptr inbounds [[S:%.*]], %S* [[A:%.*]], i64 0, i32 0
; X86-NEXT: [[TMP0:%.*]] = load i32, i32* [[FIRST_I]], align 4
; X86-NEXT: [[FIRST1_I:%.*]] = getelementptr inbounds [[S]], %S* [[B:%.*]], i64 0, i32 0
; X86-NEXT: [[TMP1:%.*]] = load i32, i32* [[FIRST1_I]], align 4
; X86-NEXT: call void (...) @foo()
; X86-NEXT: [[CMP_I:%.*]] = icmp eq i32 [[TMP0]], [[TMP1]]
; X86-NEXT: br i1 [[CMP_I]], label %"land.rhs.i+land.rhs.i.2+land.rhs.i.3", label [[OPEQ1_EXIT:%.*]]
; X86: "land.rhs.i+land.rhs.i.2+land.rhs.i.3":
; X86-NEXT: [[TMP2:%.*]] = getelementptr inbounds [[S]], %S* [[A]], i64 0, i32 1
; X86-NEXT: [[TMP3:%.*]] = getelementptr inbounds [[S]], %S* [[B]], i64 0, i32 1
; X86-NEXT: [[CSTR:%.*]] = bitcast i32* [[TMP2]] to i8*
; X86-NEXT: [[CSTR1:%.*]] = bitcast i32* [[TMP3]] to i8*
; X86-NEXT: [[MEMCMP:%.*]] = call i32 @memcmp(i8* [[CSTR]], i8* [[CSTR1]], i64 12)
; X86-NEXT: [[TMP4:%.*]] = icmp eq i32 [[MEMCMP]], 0
; X86-NEXT: br label [[OPEQ1_EXIT]]
; X86: opeq1.exit:
; X86-NEXT: [[TMP5:%.*]] = phi i1 [ false, [[ENTRY:%.*]] ], [ [[TMP4]], %"land.rhs.i+land.rhs.i.2+land.rhs.i.3" ]
; X86-NEXT: ret i1 [[TMP5]]
;
; Make sure this call is moved to the beginning of the entry block.
%S* nocapture readonly dereferenceable(16) %a,
%S* nocapture readonly dereferenceable(16) %b) local_unnamed_addr nofree nosync {
entry:
%first.i = getelementptr inbounds %S, %S* %a, i64 0, i32 0
%0 = load i32, i32* %first.i, align 4
%first1.i = getelementptr inbounds %S, %S* %b, i64 0, i32 0
%1 = load i32, i32* %first1.i, align 4
call void (...) @foo()
%cmp.i = icmp eq i32 %0, %1
br i1 %cmp.i, label %land.rhs.i, label %opeq1.exit

land.rhs.i:
%second.i = getelementptr inbounds %S, %S* %a, i64 0, i32 1
%2 = load i32, i32* %second.i, align 4
%second2.i = getelementptr inbounds %S, %S* %b, i64 0, i32 1
%3 = load i32, i32* %second2.i, align 4
%cmp2.i = icmp eq i32 %2, %3
br i1 %cmp2.i, label %land.rhs.i.2, label %opeq1.exit

land.rhs.i.2:
%third.i = getelementptr inbounds %S, %S* %a, i64 0, i32 2
%4 = load i32, i32* %third.i, align 4
%third2.i = getelementptr inbounds %S, %S* %b, i64 0, i32 2
%5 = load i32, i32* %third2.i, align 4
%cmp3.i = icmp eq i32 %4, %5
br i1 %cmp3.i, label %land.rhs.i.3, label %opeq1.exit

land.rhs.i.3:
%fourth.i = getelementptr inbounds %S, %S* %a, i64 0, i32 3
%6 = load i32, i32* %fourth.i, align 4
%fourth2.i = getelementptr inbounds %S, %S* %b, i64 0, i32 3
%7 = load i32, i32* %fourth2.i, align 4
%cmp4.i = icmp eq i32 %6, %7
br label %opeq1.exit

opeq1.exit:
%8 = phi i1 [ false, %entry ], [ false, %land.rhs.i] , [ false, %land.rhs.i.2 ], [ %cmp4.i, %land.rhs.i.3 ]
ret i1 %8
}

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