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[Test] Add missing opportunity for replacement of select with Phi

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Max Kazantsev
2020-06-17 15:33:42 +07:00
parent b21794a91c
commit 9465dd5ddd
1 changed files with 59 additions and 0 deletions
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llvm/test/Transforms/InstCombine/select.ll
+59
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@@ -1669,3 +1669,62 @@ define float @copysign_wrong_const(float %x) {
%r = select i1 %ispos, float 2.0, float -1.0
ret float %r
}
; TODO: we can replace select with a Phi.
define i32 @select_dominating_cond(i1 %cond, i32 %x, i32 %y) {
; CHECK-LABEL: @select_dominating_cond(
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 [[COND:%.*]], label [[IF_TRUE:%.*]], label [[IF_FALSE:%.*]]
; CHECK: if.true:
; CHECK-NEXT: br label [[MERGE:%.*]]
; CHECK: if.false:
; CHECK-NEXT: br label [[MERGE]]
; CHECK: merge:
; CHECK-NEXT: [[S:%.*]] = select i1 [[COND]], i32 [[X:%.*]], i32 [[Y:%.*]]
; CHECK-NEXT: ret i32 [[S]]
;
entry:
br i1 %cond, label %if.true, label %if.false
if.true:
br label %merge
if.false:
br label %merge
merge:
%s = select i1 %cond, i32 %x, i32 %y
ret i32 %s
}
; TODO: We can replace select with a Phi and then sink a and b to respective
; branches.
define i32 @select_dominating_cond_and_sink(i1 %cond, i32 %x, i32 %y) {
; CHECK-LABEL: @select_dominating_cond_and_sink(
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 [[COND:%.*]], label [[IF_TRUE:%.*]], label [[IF_FALSE:%.*]]
; CHECK: if.true:
; CHECK-NEXT: br label [[MERGE:%.*]]
; CHECK: if.false:
; CHECK-NEXT: br label [[MERGE]]
; CHECK: merge:
; CHECK-NEXT: [[B:%.*]] = mul i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[A:%.*]] = add i32 [[X]], [[Y]]
; CHECK-NEXT: [[S:%.*]] = select i1 [[COND]], i32 [[A]], i32 [[B]]
; CHECK-NEXT: ret i32 [[S]]
;
entry:
%a = add i32 %x, %y
%b = mul i32 %x, %y
br i1 %cond, label %if.true, label %if.false
if.true:
br label %merge
if.false:
br label %merge
merge:
%s = select i1 %cond, i32 %a, i32 %b
ret i32 %s
}