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|
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature
; RUN: opt < %s -passes=ipsccp -S | FileCheck %s
; PR36485
; musttail call result can\'t be replaced with a constant, unless the call
; can be removed
declare i32 @external()
define ptr @start(i8 %v) {
; CHECK-LABEL: define {{[^@]+}}@start
; CHECK-SAME: (i8 [[V:%.*]]) {
; CHECK-NEXT: [[C1:%.*]] = icmp eq i8 [[V]], 0
; CHECK-NEXT: br i1 [[C1]], label [[TRUE:%.*]], label [[FALSE:%.*]]
; CHECK: true:
; CHECK-NEXT: [[CA:%.*]] = musttail call ptr @side_effects(i8 0)
; CHECK-NEXT: ret ptr [[CA]]
; CHECK: false:
; CHECK-NEXT: [[C2:%.*]] = icmp eq i8 [[V]], 1
; CHECK-NEXT: br i1 [[C2]], label [[C2_TRUE:%.*]], label [[C2_FALSE:%.*]]
; CHECK: c2_true:
; CHECK-NEXT: ret ptr null
; CHECK: c2_false:
; CHECK-NEXT: [[CA2:%.*]] = musttail call ptr @dont_zap_me(i8 [[V]])
; CHECK-NEXT: ret ptr [[CA2]]
;
%c1 = icmp eq i8 %v, 0
br i1 %c1, label %true, label %false
true:
%ca = musttail call ptr @side_effects(i8 %v)
ret ptr %ca
false:
%c2 = icmp eq i8 %v, 1
br i1 %c2, label %c2_true, label %c2_false
c2_true:
%ca1 = musttail call ptr @no_side_effects(i8 %v)
ret ptr %ca1
c2_false:
%ca2 = musttail call ptr @dont_zap_me(i8 %v)
ret ptr %ca2
}
define internal ptr @side_effects(i8 %v) {
; CHECK-LABEL: define {{[^@]+}}@side_effects
; CHECK-SAME: (i8 [[V:%.*]]) {
; CHECK-NEXT: [[I1:%.*]] = call i32 @external()
; CHECK-NEXT: [[CA:%.*]] = musttail call ptr @start(i8 0)
; CHECK-NEXT: ret ptr [[CA]]
;
%i1 = call i32 @external()
; since this goes back to `start` the SCPP should be see that the return value
; is always `null`.
; The call can't be removed due to `external` call above, though.
%ca = musttail call ptr @start(i8 %v)
; Thus the result must be returned anyway
ret ptr %ca
}
; The call to this function is removed, so the return value must be zapped
define internal ptr @no_side_effects(i8 %v) readonly nounwind willreturn {
; CHECK-LABEL: define {{[^@]+}}@no_side_effects
; CHECK-SAME: (i8 [[V:%.*]]) #[[ATTR0:[0-9]+]] {
; CHECK-NEXT: ret ptr undef
;
ret ptr null
}
; The call to this function cannot be removed due to side effects. Thus the
; return value should stay as it is, and should not be zapped.
define internal ptr @dont_zap_me(i8 %v) {
; CHECK-LABEL: define {{[^@]+}}@dont_zap_me
; CHECK-SAME: (i8 [[V:%.*]]) {
; CHECK-NEXT: [[I1:%.*]] = call i32 @external()
; CHECK-NEXT: ret ptr null
;
%i1 = call i32 @external()
ret ptr null
}
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