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llvm-mirror/test/Transforms/InstCombine/sink_instruction.ll
Jun Bum Lim 3135fa5afa [InstCombine] Allow sinking from unique predecessor with multiple edges
Summary: We can allow sinking if the single user block has only one unique predecessor, regardless of the number of edges. Note that a switch statement with multiple cases can have the same destination.

Reviewers: mcrosier, majnemer, spatel, reames

Subscribers: reames, mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D23722

llvm-svn: 279448
2016-08-22 18:21:56 +00:00

80 lines
2.5 KiB
LLVM

; RUN: opt -instcombine -S < %s | FileCheck %s
;; This tests that the instructions in the entry blocks are sunk into each
;; arm of the 'if'.
define i32 @test1(i1 %C, i32 %A, i32 %B) {
; CHECK-LABEL: @test1(
entry:
%tmp.2 = sdiv i32 %A, %B ; <i32> [#uses=1]
%tmp.9 = add i32 %B, %A ; <i32> [#uses=1]
br i1 %C, label %then, label %endif
then: ; preds = %entry
ret i32 %tmp.9
endif: ; preds = %entry
; CHECK: sdiv i32
; CHECK-NEXT: ret i32
ret i32 %tmp.2
}
;; PHI use, sink divide before call.
define i32 @test2(i32 %x) nounwind ssp {
; CHECK-LABEL: @test2(
; CHECK-NOT: sdiv i32
entry:
br label %bb
bb: ; preds = %bb2, %entry
%x_addr.17 = phi i32 [ %x, %entry ], [ %x_addr.0, %bb2 ] ; <i32> [#uses=4]
%i.06 = phi i32 [ 0, %entry ], [ %4, %bb2 ] ; <i32> [#uses=1]
%0 = add nsw i32 %x_addr.17, 1 ; <i32> [#uses=1]
%1 = sdiv i32 %0, %x_addr.17 ; <i32> [#uses=1]
%2 = icmp eq i32 %x_addr.17, 0 ; <i1> [#uses=1]
br i1 %2, label %bb1, label %bb2
bb1: ; preds = %bb
; CHECK: bb1:
; CHECK-NEXT: add nsw i32 %x_addr.17, 1
; CHECK-NEXT: sdiv i32
; CHECK-NEXT: tail call i32 @bar()
%3 = tail call i32 @bar() nounwind ; <i32> [#uses=0]
br label %bb2
bb2: ; preds = %bb, %bb1
%x_addr.0 = phi i32 [ %1, %bb1 ], [ %x_addr.17, %bb ] ; <i32> [#uses=2]
%4 = add nsw i32 %i.06, 1 ; <i32> [#uses=2]
%exitcond = icmp eq i32 %4, 1000000 ; <i1> [#uses=1]
br i1 %exitcond, label %bb4, label %bb
bb4: ; preds = %bb2
ret i32 %x_addr.0
}
declare i32 @bar()
define i32 @test3(i32* nocapture readonly %P, i32 %i) {
entry:
%idxprom = sext i32 %i to i64
%arrayidx = getelementptr inbounds i32, i32* %P, i64 %idxprom
%0 = load i32, i32* %arrayidx, align 4
switch i32 %i, label %sw.epilog [
i32 5, label %sw.bb
i32 2, label %sw.bb
]
sw.bb: ; preds = %entry, %entry
; CHECK-LABEL: sw.bb:
; CHECK: %idxprom = sext i32 %i to i64
; CHECK: %arrayidx = getelementptr inbounds i32, i32* %P, i64 %idxprom
; CHECK: %0 = load i32, i32* %arrayidx, align 4
%add = add nsw i32 %0, %i
br label %sw.epilog
sw.epilog: ; preds = %entry, %sw.bb
%sum.0 = phi i32 [ %add, %sw.bb ], [ 0, %entry ]
ret i32 %sum.0
}