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llvm-project/llvm/test/CodeGen/AArch64/dag-combine-select.ll

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[AArch64] Enable PostRAScheduler for AArch64 generic build. Disable post-ra scheduler for perturbed tests to appease the bots and to preserve the history of the tests. http://reviews.llvm.org/D15652 llvm-svn: 256158
2015-12-21 22:43:45 +08:00
; RUN: llc -disable-post-ra -o - %s | FileCheck %s
DAGCombiner: Optimize SELECTs first before turning them into SELECT_CC This is part of http://reviews.llvm.org/D11616 - I just decided to split this up into a separate commit. llvm-svn: 245349
2015-08-19 04:48:29 +08:00
target triple = "arm64--"
DAGCombiner: Improve DAGCombiner select normalization The current code normalizes select(C0, x, select(C1, x, y)) towards select(C0|C1, x, y) if the targets prefers that form. This patch adds an additional rule that if the select(C1, x, y) part already exists in the function then we want to normalize into the other direction because the effects of reusing the existing value are bigger than transforming into the target preferred form. This addresses regressions following r238793, see also: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150727/290272.html Differential Revision: http://reviews.llvm.org/D11616 llvm-svn: 245350
2015-08-19 04:48:36 +08:00
@out = internal global i32 0, align 4
DAGCombiner: Optimize SELECTs first before turning them into SELECT_CC This is part of http://reviews.llvm.org/D11616 - I just decided to split this up into a separate commit. llvm-svn: 245349
2015-08-19 04:48:29 +08:00
; Ensure that we transform select(C0, x, select(C1, x, y)) towards
; select(C0 | C1, x, y) so we can use CMP;CCMP for the implementation.
; CHECK-LABEL: test0:
; CHECK: cmp w0, #7
; CHECK: ccmp w1, #0, #0, ne
; CHECK: csel w0, w1, w2, gt
; CHECK: ret
define i32 @test0(i32 %v0, i32 %v1, i32 %v2) {
%cmp1 = icmp eq i32 %v0, 7
%cmp2 = icmp sgt i32 %v1, 0
%sel0 = select i1 %cmp1, i32 %v1, i32 %v2
%sel1 = select i1 %cmp2, i32 %v1, i32 %sel0
ret i32 %sel1
}
DAGCombiner: Improve DAGCombiner select normalization The current code normalizes select(C0, x, select(C1, x, y)) towards select(C0|C1, x, y) if the targets prefers that form. This patch adds an additional rule that if the select(C1, x, y) part already exists in the function then we want to normalize into the other direction because the effects of reusing the existing value are bigger than transforming into the target preferred form. This addresses regressions following r238793, see also: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150727/290272.html Differential Revision: http://reviews.llvm.org/D11616 llvm-svn: 245350
2015-08-19 04:48:36 +08:00
; Usually we keep select(C0 | C1, x, y) as is on aarch64 to create CMP;CCMP
; sequences. This case should be transformed to select(C0, select(C1, x, y), y)
; anyway to get CSE effects.
; CHECK-LABEL: test1:
; CHECK-NOT: ccmp
; CHECK: cmp w0, #7
; CHECK: adrp x[[OUTNUM:[0-9]+]], out
; CHECK: csel w[[SEL0NUM:[0-9]+]], w1, w2, eq
; CHECK: cmp w[[SEL0NUM]], #13
; CHECK: csel w[[SEL1NUM:[0-9]+]], w1, w2, lo
; CHECK: cmp w0, #42
; CHECK: csel w[[SEL2NUM:[0-9]+]], w1, w[[SEL1NUM]], eq
; CHECK: str w[[SEL1NUM]], [x[[OUTNUM]], :lo12:out]
; CHECK: str w[[SEL2NUM]], [x[[OUTNUM]], :lo12:out]
; CHECK: ret
define void @test1(i32 %bitset, i32 %val0, i32 %val1) {
%cmp1 = icmp eq i32 %bitset, 7
%cond = select i1 %cmp1, i32 %val0, i32 %val1
%cmp5 = icmp ult i32 %cond, 13
%cond11 = select i1 %cmp5, i32 %val0, i32 %val1
%cmp3 = icmp eq i32 %bitset, 42
%or.cond = or i1 %cmp3, %cmp5
%cond17 = select i1 %or.cond, i32 %val0, i32 %val1
store volatile i32 %cond11, i32* @out, align 4
store volatile i32 %cond17, i32* @out, align 4
ret void
}