Files
clang-p2996/llvm/test/CodeGen/X86/usub_inc_iv.ll
Max Kazantsev 418c218efa Return "[Codegenprepare][X86] Use usub with overflow opt for IV increment"
The patch did not account for one corner case where cmp does not dominate
the loop latch. This patch adds this check, hopefully it's cheap because
the CFG does not change during the transform, so DT queries should be
executed quickly.

If you see compile time slowness from this, please revert.

Differential Revision: https://reviews.llvm.org/D96119
2021-02-11 19:49:23 +07:00

313 lines
12 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -mtriple=x86_64-linux -codegenprepare -S < %s | FileCheck %s
define i32 @test_01(i32* %p, i64 %len, i32 %x) {
; CHECK-LABEL: @test_01(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[MATH:%.*]], [[BACKEDGE:%.*]] ], [ [[LEN:%.*]], [[ENTRY:%.*]] ]
; CHECK-NEXT: [[TMP0:%.*]] = call { i64, i1 } @llvm.usub.with.overflow.i64(i64 [[IV]], i64 1)
; CHECK-NEXT: [[MATH]] = extractvalue { i64, i1 } [[TMP0]], 0
; CHECK-NEXT: [[OV:%.*]] = extractvalue { i64, i1 } [[TMP0]], 1
; CHECK-NEXT: br i1 [[OV]], label [[EXIT:%.*]], label [[BACKEDGE]]
; CHECK: backedge:
; CHECK-NEXT: [[SUNKADDR:%.*]] = mul i64 [[IV]], 4
; CHECK-NEXT: [[TMP1:%.*]] = bitcast i32* [[P:%.*]] to i8*
; CHECK-NEXT: [[SUNKADDR1:%.*]] = getelementptr i8, i8* [[TMP1]], i64 [[SUNKADDR]]
; CHECK-NEXT: [[SUNKADDR2:%.*]] = getelementptr i8, i8* [[SUNKADDR1]], i64 -4
; CHECK-NEXT: [[TMP2:%.*]] = bitcast i8* [[SUNKADDR2]] to i32*
; CHECK-NEXT: [[LOADED:%.*]] = load atomic i32, i32* [[TMP2]] unordered, align 4
; CHECK-NEXT: [[COND_2:%.*]] = icmp eq i32 [[LOADED]], [[X:%.*]]
; CHECK-NEXT: br i1 [[COND_2]], label [[FAILURE:%.*]], label [[LOOP]]
; CHECK: exit:
; CHECK-NEXT: ret i32 -1
; CHECK: failure:
; CHECK-NEXT: unreachable
;
entry:
%scevgep = getelementptr i32, i32* %p, i64 -1
br label %loop
loop: ; preds = %backedge, %entry
%iv = phi i64 [ %iv.next, %backedge ], [ %len, %entry ]
%iv.next = add i64 %iv, -1
%cond_1 = icmp eq i64 %iv, 0
br i1 %cond_1, label %exit, label %backedge
backedge: ; preds = %loop
%scevgep1 = getelementptr i32, i32* %scevgep, i64 %iv
%loaded = load atomic i32, i32* %scevgep1 unordered, align 4
%cond_2 = icmp eq i32 %loaded, %x
br i1 %cond_2, label %failure, label %loop
exit: ; preds = %loop
ret i32 -1
failure: ; preds = %backedge
unreachable
}
; Similar to test_01, but with different offset.
define i32 @test_01a(i32* %p, i64 %len, i32 %x) {
; CHECK-LABEL: @test_01a(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[MATH:%.*]], [[BACKEDGE:%.*]] ], [ [[LEN:%.*]], [[ENTRY:%.*]] ]
; CHECK-NEXT: [[TMP0:%.*]] = call { i64, i1 } @llvm.usub.with.overflow.i64(i64 [[IV]], i64 1)
; CHECK-NEXT: [[MATH]] = extractvalue { i64, i1 } [[TMP0]], 0
; CHECK-NEXT: [[OV:%.*]] = extractvalue { i64, i1 } [[TMP0]], 1
; CHECK-NEXT: br i1 [[OV]], label [[EXIT:%.*]], label [[BACKEDGE]]
; CHECK: backedge:
; CHECK-NEXT: [[SUNKADDR:%.*]] = mul i64 [[IV]], 4
; CHECK-NEXT: [[TMP1:%.*]] = bitcast i32* [[P:%.*]] to i8*
; CHECK-NEXT: [[SUNKADDR1:%.*]] = getelementptr i8, i8* [[TMP1]], i64 [[SUNKADDR]]
; CHECK-NEXT: [[SUNKADDR2:%.*]] = getelementptr i8, i8* [[SUNKADDR1]], i64 -28
; CHECK-NEXT: [[TMP2:%.*]] = bitcast i8* [[SUNKADDR2]] to i32*
; CHECK-NEXT: [[LOADED:%.*]] = load atomic i32, i32* [[TMP2]] unordered, align 4
; CHECK-NEXT: [[COND_2:%.*]] = icmp eq i32 [[LOADED]], [[X:%.*]]
; CHECK-NEXT: br i1 [[COND_2]], label [[FAILURE:%.*]], label [[LOOP]]
; CHECK: exit:
; CHECK-NEXT: ret i32 -1
; CHECK: failure:
; CHECK-NEXT: unreachable
;
entry:
%scevgep = getelementptr i32, i32* %p, i64 -7
br label %loop
loop: ; preds = %backedge, %entry
%iv = phi i64 [ %iv.next, %backedge ], [ %len, %entry ]
%iv.next = add i64 %iv, -1
%cond_1 = icmp eq i64 %iv, 0
br i1 %cond_1, label %exit, label %backedge
backedge: ; preds = %loop
%scevgep1 = getelementptr i32, i32* %scevgep, i64 %iv
%loaded = load atomic i32, i32* %scevgep1 unordered, align 4
%cond_2 = icmp eq i32 %loaded, %x
br i1 %cond_2, label %failure, label %loop
exit: ; preds = %loop
ret i32 -1
failure: ; preds = %backedge
unreachable
}
; TODO: We can use trick with usub here.
define i32 @test_02(i32* %p, i64 %len, i32 %x) {
; CHECK-LABEL: @test_02(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[MATH:%.*]], [[BACKEDGE:%.*]] ], [ [[LEN:%.*]], [[ENTRY:%.*]] ]
; CHECK-NEXT: [[TMP0:%.*]] = call { i64, i1 } @llvm.usub.with.overflow.i64(i64 [[IV]], i64 1)
; CHECK-NEXT: [[MATH]] = extractvalue { i64, i1 } [[TMP0]], 0
; CHECK-NEXT: [[OV:%.*]] = extractvalue { i64, i1 } [[TMP0]], 1
; CHECK-NEXT: br i1 [[OV]], label [[EXIT:%.*]], label [[BACKEDGE]]
; CHECK: backedge:
; CHECK-NEXT: [[SUNKADDR:%.*]] = mul i64 [[IV]], 4
; CHECK-NEXT: [[TMP1:%.*]] = bitcast i32* [[P:%.*]] to i8*
; CHECK-NEXT: [[SUNKADDR1:%.*]] = getelementptr i8, i8* [[TMP1]], i64 [[SUNKADDR]]
; CHECK-NEXT: [[SUNKADDR2:%.*]] = getelementptr i8, i8* [[SUNKADDR1]], i64 -4
; CHECK-NEXT: [[TMP2:%.*]] = bitcast i8* [[SUNKADDR2]] to i32*
; CHECK-NEXT: [[LOADED:%.*]] = load atomic i32, i32* [[TMP2]] unordered, align 4
; CHECK-NEXT: [[COND_2:%.*]] = icmp eq i32 [[LOADED]], [[X:%.*]]
; CHECK-NEXT: br i1 [[COND_2]], label [[FAILURE:%.*]], label [[LOOP]]
; CHECK: exit:
; CHECK-NEXT: ret i32 -1
; CHECK: failure:
; CHECK-NEXT: unreachable
;
entry:
%scevgep = getelementptr i32, i32* %p, i64 -1
br label %loop
loop: ; preds = %backedge, %entry
%iv = phi i64 [ %iv.next, %backedge ], [ %len, %entry ]
%cond_1 = icmp eq i64 %iv, 0
br i1 %cond_1, label %exit, label %backedge
backedge: ; preds = %loop
%scevgep1 = getelementptr i32, i32* %scevgep, i64 %iv
%loaded = load atomic i32, i32* %scevgep1 unordered, align 4
%cond_2 = icmp eq i32 %loaded, %x
%iv.next = add i64 %iv, -1
br i1 %cond_2, label %failure, label %loop
exit: ; preds = %loop
ret i32 -1
failure: ; preds = %backedge
unreachable
}
declare i1 @use(i64 %x)
declare i1 @some_cond()
; Make sure we do not move the increment below the point where it is used.
define i32 @test_03_neg(i32* %p, i64 %len, i32 %x) {
; CHECK-LABEL: @test_03_neg(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ], [ [[LEN:%.*]], [[ENTRY:%.*]] ]
; CHECK-NEXT: [[IV_NEXT]] = add i64 [[IV]], -1
; CHECK-NEXT: [[COND_0:%.*]] = call i1 @use(i64 [[IV_NEXT]])
; CHECK-NEXT: br i1 [[COND_0]], label [[MIDDLE:%.*]], label [[FAILURE:%.*]]
; CHECK: middle:
; CHECK-NEXT: [[COND_1:%.*]] = icmp eq i64 [[IV]], 0
; CHECK-NEXT: br i1 [[COND_1]], label [[EXIT:%.*]], label [[BACKEDGE]]
; CHECK: backedge:
; CHECK-NEXT: [[SUNKADDR:%.*]] = mul i64 [[IV]], 4
; CHECK-NEXT: [[TMP0:%.*]] = bitcast i32* [[P:%.*]] to i8*
; CHECK-NEXT: [[SUNKADDR1:%.*]] = getelementptr i8, i8* [[TMP0]], i64 [[SUNKADDR]]
; CHECK-NEXT: [[SUNKADDR2:%.*]] = getelementptr i8, i8* [[SUNKADDR1]], i64 -4
; CHECK-NEXT: [[TMP1:%.*]] = bitcast i8* [[SUNKADDR2]] to i32*
; CHECK-NEXT: [[LOADED:%.*]] = load atomic i32, i32* [[TMP1]] unordered, align 4
; CHECK-NEXT: [[COND_2:%.*]] = icmp eq i32 [[LOADED]], [[X:%.*]]
; CHECK-NEXT: br i1 [[COND_2]], label [[FAILURE]], label [[LOOP]]
; CHECK: exit:
; CHECK-NEXT: ret i32 -1
; CHECK: failure:
; CHECK-NEXT: unreachable
;
entry:
%scevgep = getelementptr i32, i32* %p, i64 -1
br label %loop
loop: ; preds = %backedge, %entry
%iv = phi i64 [ %iv.next, %backedge ], [ %len, %entry ]
%iv.next = add i64 %iv, -1
%cond_0 = call i1 @use(i64 %iv.next)
br i1 %cond_0, label %middle, label %failure
middle:
%cond_1 = icmp eq i64 %iv, 0
br i1 %cond_1, label %exit, label %backedge
backedge: ; preds = %loop
%scevgep1 = getelementptr i32, i32* %scevgep, i64 %iv
%loaded = load atomic i32, i32* %scevgep1 unordered, align 4
%cond_2 = icmp eq i32 %loaded, %x
br i1 %cond_2, label %failure, label %loop
exit: ; preds = %loop
ret i32 -1
failure: ; preds = %backedge
unreachable
}
define i32 @test_04_neg(i32* %p, i64 %len, i32 %x) {
; CHECK-LABEL: @test_04_neg(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ], [ [[LEN:%.*]], [[ENTRY:%.*]] ]
; CHECK-NEXT: br label [[INNER:%.*]]
; CHECK: inner:
; CHECK-NEXT: [[COND_1:%.*]] = icmp eq i64 [[IV]], 0
; CHECK-NEXT: br i1 [[COND_1]], label [[INNER_BACKEDGE:%.*]], label [[EXIT:%.*]]
; CHECK: inner_backedge:
; CHECK-NEXT: [[COND_INNER:%.*]] = call i1 @some_cond()
; CHECK-NEXT: br i1 [[COND_INNER]], label [[INNER]], label [[BACKEDGE]]
; CHECK: backedge:
; CHECK-NEXT: [[SUNKADDR:%.*]] = mul i64 [[IV]], 4
; CHECK-NEXT: [[TMP0:%.*]] = bitcast i32* [[P:%.*]] to i8*
; CHECK-NEXT: [[SUNKADDR1:%.*]] = getelementptr i8, i8* [[TMP0]], i64 [[SUNKADDR]]
; CHECK-NEXT: [[SUNKADDR2:%.*]] = getelementptr i8, i8* [[SUNKADDR1]], i64 -4
; CHECK-NEXT: [[TMP1:%.*]] = bitcast i8* [[SUNKADDR2]] to i32*
; CHECK-NEXT: [[LOADED:%.*]] = load atomic i32, i32* [[TMP1]] unordered, align 4
; CHECK-NEXT: [[COND_2:%.*]] = icmp eq i32 [[LOADED]], [[X:%.*]]
; CHECK-NEXT: [[IV_NEXT]] = add i64 [[IV]], -1
; CHECK-NEXT: br i1 [[COND_2]], label [[FAILURE:%.*]], label [[LOOP]]
; CHECK: exit:
; CHECK-NEXT: ret i32 -1
; CHECK: failure:
; CHECK-NEXT: unreachable
;
entry:
%scevgep = getelementptr i32, i32* %p, i64 -1
br label %loop
loop:
%iv = phi i64 [ %iv.next, %backedge ], [ %len, %entry ]
br label %inner
inner:
%cond_1 = icmp eq i64 %iv, 0
br i1 %cond_1, label %inner_backedge, label %exit
inner_backedge:
%cond_inner = call i1 @some_cond()
br i1 %cond_inner, label %inner, label %backedge
backedge:
%scevgep1 = getelementptr i32, i32* %scevgep, i64 %iv
%loaded = load atomic i32, i32* %scevgep1 unordered, align 4
%cond_2 = icmp eq i32 %loaded, %x
%iv.next = add i64 %iv, -1
br i1 %cond_2, label %failure, label %loop
exit:
ret i32 -1
failure:
unreachable
}
; Here Cmp does not dominate latch.
define i32 @test_05_neg(i32* %p, i64 %len, i32 %x, i1 %cond) {
; CHECK-LABEL: @test_05_neg(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ], [ [[LEN:%.*]], [[ENTRY:%.*]] ]
; CHECK-NEXT: [[IV_NEXT]] = add i64 [[IV]], -1
; CHECK-NEXT: br i1 [[COND:%.*]], label [[IF_TRUE:%.*]], label [[BACKEDGE]]
; CHECK: if.true:
; CHECK-NEXT: [[COND_1:%.*]] = icmp eq i64 [[IV]], 0
; CHECK-NEXT: br i1 [[COND_1]], label [[EXIT:%.*]], label [[BACKEDGE]]
; CHECK: backedge:
; CHECK-NEXT: [[SUNKADDR:%.*]] = mul i64 [[IV]], 4
; CHECK-NEXT: [[TMP0:%.*]] = bitcast i32* [[P:%.*]] to i8*
; CHECK-NEXT: [[SUNKADDR1:%.*]] = getelementptr i8, i8* [[TMP0]], i64 [[SUNKADDR]]
; CHECK-NEXT: [[SUNKADDR2:%.*]] = getelementptr i8, i8* [[SUNKADDR1]], i64 -4
; CHECK-NEXT: [[TMP1:%.*]] = bitcast i8* [[SUNKADDR2]] to i32*
; CHECK-NEXT: [[LOADED:%.*]] = load atomic i32, i32* [[TMP1]] unordered, align 4
; CHECK-NEXT: [[COND_2:%.*]] = icmp eq i32 [[LOADED]], [[X:%.*]]
; CHECK-NEXT: br i1 [[COND_2]], label [[FAILURE:%.*]], label [[LOOP]]
; CHECK: exit:
; CHECK-NEXT: ret i32 -1
; CHECK: failure:
; CHECK-NEXT: unreachable
;
entry:
%scevgep = getelementptr i32, i32* %p, i64 -1
br label %loop
loop: ; preds = %backedge, %entry
%iv = phi i64 [ %iv.next, %backedge ], [ %len, %entry ]
%iv.next = add i64 %iv, -1
br i1 %cond, label %if.true, label %backedge
if.true:
%cond_1 = icmp eq i64 %iv, 0
br i1 %cond_1, label %exit, label %backedge
backedge: ; preds = %loop
%scevgep1 = getelementptr i32, i32* %scevgep, i64 %iv
%loaded = load atomic i32, i32* %scevgep1 unordered, align 4
%cond_2 = icmp eq i32 %loaded, %x
br i1 %cond_2, label %failure, label %loop
exit: ; preds = %loop
ret i32 -1
failure: ; preds = %backedge
unreachable
}