[InstCombine] add/adjust tests for fcmp+select substitution; NFC

There was no coverage for at least 2 out of the 4 patterns because
of fcmp canonicalization. The tests and code should be moved to
InstSimplify in a follow-up because this doesn't create any new values.

llvm-svn: 346150

1 files changed, 91 insertions, 28 deletions

diff --git a/llvm/test/Transforms/InstCombine/fcmp-select.ll b/llvm/test/Transforms/InstCombine/fcmp-select.ll
index e04ab3e8923..7fc59bbcb7d 100644
--- a/llvm/test/Transforms/InstCombine/fcmp-select.ll
+++ b/llvm/test/Transforms/InstCombine/fcmp-select.ll
@@ -1,53 +1,116 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -instcombine -S | FileCheck %s
 
+declare void @use(i1)
+
+; X == 42.0 ? X : 42.0 --> 42.0
+
+define double @oeq(double %x) {
+; CHECK-LABEL: @oeq(
+; CHECK-NEXT:    [[CMP:%.*]] = fcmp oeq double [[X:%.*]], 4.200000e+01
+; CHECK-NEXT:    call void @use(i1 [[CMP]])
+; CHECK-NEXT:    ret double 4.200000e+01
+;
+  %cmp = fcmp oeq double %x, 42.0
+  call void @use(i1 %cmp)      ; extra use to thwart predicate canonicalization
+  %cond = select i1 %cmp, double %x, double 42.0
+  ret double %cond
+}
+
+; X == 42.0 ? 42.0 : X --> X
+
+define float @oeq_swapped(float %x) {
+; CHECK-LABEL: @oeq_swapped(
+; CHECK-NEXT:    [[CMP:%.*]] = fcmp oeq float [[X:%.*]], 4.200000e+01
+; CHECK-NEXT:    call void @use(i1 [[CMP]])
+; CHECK-NEXT:    ret float [[X]]
+;
+  %cmp = fcmp oeq float %x, 42.0
+  call void @use(i1 %cmp)      ; extra use to thwart predicate canonicalization
+  %cond = select i1 %cmp, float 42.0, float %x
+  ret float %cond
+}
+
 ; x != y ? x : y -> x if it's the right kind of != and at least
 ; one of x and y is not negative zero.
 
-; CHECK: f0
-; CHECK: ret double %x
-define double @f0(double %x) nounwind readnone {
-entry:
-  %cmp = fcmp une double %x, -1.0
-  %cond = select i1 %cmp, double %x, double -1.0
+; X != 42.0 ? X : 42.0 --> X
+
+define double @une(double %x) {
+; CHECK-LABEL: @une(
+; CHECK-NEXT:    [[CMP:%.*]] = fcmp une double [[X:%.*]], 4.200000e+01
+; CHECK-NEXT:    call void @use(i1 [[CMP]])
+; CHECK-NEXT:    ret double [[X]]
+;
+  %cmp = fcmp une double %x, 42.0
+  call void @use(i1 %cmp)      ; extra use to thwart predicate canonicalization
+  %cond = select i1 %cmp, double %x, double 42.0
   ret double %cond
 }
-; CHECK: f1
-; CHECK: ret double -1.000000e+00
-define double @f1(double %x) nounwind readnone {
-entry:
-  %cmp = fcmp une double %x, -1.0
-  %cond = select i1 %cmp, double -1.0, double %x
+
+; X != 42.0 ? 42.0 : X --> 42.0
+
+define double @une_swapped(double %x) {
+; CHECK-LABEL: @une_swapped(
+; CHECK-NEXT:    [[CMP:%.*]] = fcmp une double [[X:%.*]], 4.200000e+01
+; CHECK-NEXT:    call void @use(i1 [[CMP]])
+; CHECK-NEXT:    ret double 4.200000e+01
+;
+  %cmp = fcmp une double %x, 42.0
+  call void @use(i1 %cmp)      ; extra use to thwart predicate canonicalization
+  %cond = select i1 %cmp, double 42.0, double %x
   ret double %cond
 }
-; CHECK: f2
-; CHECK: ret double %cond
-define double @f2(double %x, double %y) nounwind readnone {
-entry:
+
+define double @une_could_be_negzero(double %x, double %y) {
+; CHECK-LABEL: @une_could_be_negzero(
+; CHECK-NEXT:    [[CMP:%.*]] = fcmp une double [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use(i1 [[CMP]])
+; CHECK-NEXT:    [[COND:%.*]] = select i1 [[CMP]], double [[X]], double [[Y]]
+; CHECK-NEXT:    ret double [[COND]]
+;
   %cmp = fcmp une double %x, %y
+  call void @use(i1 %cmp)      ; extra use to thwart predicate canonicalization
   %cond = select i1 %cmp, double %x, double %y
   ret double %cond
 }
-; CHECK: f3
-; CHECK: ret double %cond
-define double @f3(double %x, double %y) nounwind readnone {
-entry:
+
+define double @une_swapped_could_be_negzero(double %x, double %y) {
+; CHECK-LABEL: @une_swapped_could_be_negzero(
+; CHECK-NEXT:    [[CMP:%.*]] = fcmp une double [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use(i1 [[CMP]])
+; CHECK-NEXT:    [[COND:%.*]] = select i1 [[CMP]], double [[Y]], double [[X]]
+; CHECK-NEXT:    ret double [[COND]]
+;
   %cmp = fcmp une double %x, %y
+  call void @use(i1 %cmp)      ; extra use to thwart predicate canonicalization
   %cond = select i1 %cmp, double %y, double %x
   ret double %cond
 }
-; CHECK: f4
-; CHECK: ret double %cond
-define double @f4(double %x) nounwind readnone {
-entry:
+
+define double @one(double %x) {
+; CHECK-LABEL: @one(
+; CHECK-NEXT:    [[CMP:%.*]] = fcmp one double [[X:%.*]], -1.000000e+00
+; CHECK-NEXT:    call void @use(i1 [[CMP]])
+; CHECK-NEXT:    [[COND:%.*]] = select i1 [[CMP]], double [[X]], double -1.000000e+00
+; CHECK-NEXT:    ret double [[COND]]
+;
   %cmp = fcmp one double %x, -1.0
+  call void @use(i1 %cmp)      ; extra use to thwart predicate canonicalization
   %cond = select i1 %cmp, double %x, double -1.0
   ret double %cond
 }
-; CHECK: f5
-; CHECK: ret double %cond
-define double @f5(double %x) nounwind readnone {
-entry:
+
+define double @one_swapped(double %x) {
+; CHECK-LABEL: @one_swapped(
+; CHECK-NEXT:    [[CMP:%.*]] = fcmp one double [[X:%.*]], -1.000000e+00
+; CHECK-NEXT:    call void @use(i1 [[CMP]])
+; CHECK-NEXT:    [[COND:%.*]] = select i1 [[CMP]], double -1.000000e+00, double [[X]]
+; CHECK-NEXT:    ret double [[COND]]
+;
   %cmp = fcmp one double %x, -1.0
+  call void @use(i1 %cmp)      ; extra use to thwart predicate canonicalization
   %cond = select i1 %cmp, double -1.0, double %x
   ret double %cond
 }
+