Bug 21610: Canonicalize min/max fcmp selects to use ordered comparisons

llvm-svn: 222705

2 files changed, 133 insertions, 8 deletions

diff --git a/llvm/test/Transforms/InstCombine/unordered-fcmp-select.ll b/llvm/test/Transforms/InstCombine/unordered-fcmp-select.ll
new file mode 100644
index 00000000000..0eb729047e7
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/unordered-fcmp-select.ll
@@ -0,0 +1,125 @@
+; RUN: opt -S -instcombine < %s | FileCheck %s
+
+; CHECK-LABEL: @select_max_ugt(
+; CHECK: %cmp.inv = fcmp ole float %a, %b
+; CHECK-NEXT: %sel = select i1 %cmp.inv, float %b, float %a
+; CHECK-NEXT: ret float %sel
+define float @select_max_ugt(float %a, float %b) {
+  %cmp = fcmp ugt float %a, %b
+  %sel = select i1 %cmp, float %a, float %b
+  ret float %sel
+}
+
+; CHECK-LABEL: @select_max_uge(
+; CHECK: %cmp.inv = fcmp olt float %a, %b
+; CHECK-NEXT: %sel = select i1 %cmp.inv, float %b, float %a
+; CHECK-NEXT: ret float %sel
+define float @select_max_uge(float %a, float %b) {
+  %cmp = fcmp uge float %a, %b
+  %sel = select i1 %cmp, float %a, float %b
+  ret float %sel
+}
+
+; CHECK-LABEL: @select_min_ugt(
+; CHECK: %cmp.inv = fcmp ole float %a, %b
+; CHECK-NEXT: %sel = select i1 %cmp.inv, float %a, float %b
+; CHECK-NEXT: ret float %sel
+define float @select_min_ugt(float %a, float %b) {
+  %cmp = fcmp ugt float %a, %b
+  %sel = select i1 %cmp, float %b, float %a
+  ret float %sel
+}
+
+; CHECK-LABEL: @select_min_uge(
+; CHECK: %cmp.inv = fcmp olt float %a, %b
+; CHECK-NEXT: %sel = select i1 %cmp.inv, float %a, float %b
+; CHECK-NEXT: ret float %sel
+define float @select_min_uge(float %a, float %b) {
+  %cmp = fcmp uge float %a, %b
+  %sel = select i1 %cmp, float %b, float %a
+  ret float %sel
+}
+
+; CHECK-LABEL: @select_max_ult(
+; CHECK: %cmp.inv = fcmp oge float %a, %b
+; CHECK-NEXT: %sel = select i1 %cmp.inv, float %a, float %b
+; CHECK-NEXT: ret float %sel
+define float @select_max_ult(float %a, float %b) {
+  %cmp = fcmp ult float %a, %b
+  %sel = select i1 %cmp, float %b, float %a
+  ret float %sel
+}
+
+; CHECK-LABEL: @select_max_ule(
+; CHECK: %cmp.inv = fcmp ogt float %a, %b
+; CHECK-NEXT: %sel = select i1 %cmp.inv, float %a, float %b
+; CHECK: ret float %sel
+define float @select_max_ule(float %a, float %b) {
+  %cmp = fcmp ule float %a, %b
+  %sel = select i1 %cmp, float %b, float %a
+  ret float %sel
+}
+
+; CHECK-LABEL: @select_min_ult(
+; CHECK: %cmp.inv = fcmp oge float %a, %b
+; CHECK-NEXT: %sel = select i1 %cmp.inv, float %b, float %a
+; CHECK-NEXT: ret float %sel
+define float @select_min_ult(float %a, float %b) {
+  %cmp = fcmp ult float %a, %b
+  %sel = select i1 %cmp, float %a, float %b
+  ret float %sel
+}
+
+; CHECK-LABEL: @select_min_ule(
+; CHECK: %cmp.inv = fcmp ogt float %a, %b
+; CHECK-NEXT: %sel = select i1 %cmp.inv, float %b, float %a
+; CHECK-NEXT: ret float %sel
+define float @select_min_ule(float %a, float %b) {
+  %cmp = fcmp ule float %a, %b
+  %sel = select i1 %cmp, float %a, float %b
+  ret float %sel
+}
+
+; CHECK-LABEL: @select_fcmp_une(
+; CHECK:  %cmp.inv = fcmp oeq float %a, %b
+; CHECK-NEXT:  %sel = select i1 %cmp.inv, float %b, float %a
+; CHECK-NEXT: ret float %sel
+define float @select_fcmp_une(float %a, float %b) {
+  %cmp = fcmp une float %a, %b
+  %sel = select i1 %cmp, float %a, float %b
+  ret float %sel
+}
+
+; CHECK-LABEL: @select_fcmp_ueq
+; CHECK:  %cmp.inv = fcmp one float %a, %b
+; CHECK-NEXT:  %sel = select i1 %cmp.inv, float %b, float %a
+; CHECK-NEXT: ret float %sel
+define float @select_fcmp_ueq(float %a, float %b) {
+  %cmp = fcmp ueq float %a, %b
+  %sel = select i1 %cmp, float %a, float %b
+  ret float %sel
+}
+
+declare void @foo(i1)
+
+; CHECK-LABEL: @select_max_ugt_2_use_cmp(
+; CHECK: fcmp ugt
+; CHECK-NOT: fcmp
+; CHECK: ret
+define float @select_max_ugt_2_use_cmp(float %a, float %b) {
+  %cmp = fcmp ugt float %a, %b
+  call void @foo(i1 %cmp)
+  %sel = select i1 %cmp, float %a, float %b
+  ret float %sel
+}
+
+; CHECK-LABEL: @select_min_uge_2_use_cmp(
+; CHECK: fcmp uge
+; CHECK-NOT: fcmp
+; CHECK: ret
+define float @select_min_uge_2_use_cmp(float %a, float %b) {
+  %cmp = fcmp uge float %a, %b
+  call void @foo(i1 %cmp)
+  %sel = select i1 %cmp, float %b, float %a
+  ret float %sel
+}
diff --git a/llvm/test/Transforms/LoopVectorize/minmax_reduction.ll b/llvm/test/Transforms/LoopVectorize/minmax_reduction.ll
index e73e69db570..1984cdd892d 100644
--- a/llvm/test/Transforms/LoopVectorize/minmax_reduction.ll
+++ b/llvm/test/Transforms/LoopVectorize/minmax_reduction.ll
@@ -516,7 +516,7 @@ for.end:
 }
 
 ; CHECK-LABEL: @unordered_max_red_float(
-; CHECK: fcmp ugt <2 x float>
+; CHECK: fcmp ole <2 x float>
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp ogt <2 x float>
@@ -542,7 +542,7 @@ for.end:
 }
 
 ; CHECK-LABEL: @unordered_max_red_float_ge(
-; CHECK: fcmp uge <2 x float>
+; CHECK: fcmp olt <2 x float>
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp ogt <2 x float>
@@ -568,7 +568,7 @@ for.end:
 }
 
 ; CHECK-LABEL: @inverted_unordered_max_red_float(
-; CHECK: fcmp ult <2 x float>
+; CHECK: fcmp oge <2 x float>
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp ogt <2 x float>
@@ -594,7 +594,7 @@ for.end:
 }
 
 ; CHECK-LABEL: @inverted_unordered_max_red_float_le(
-; CHECK: fcmp ule <2 x float>
+; CHECK: fcmp ogt <2 x float>
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp ogt <2 x float>
@@ -727,7 +727,7 @@ for.end:
 }
 
 ; CHECK-LABEL: @unordered_min_red_float(
-; CHECK: fcmp ult <2 x float>
+; CHECK: fcmp oge <2 x float>
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp olt <2 x float>
@@ -753,7 +753,7 @@ for.end:
 }
 
 ; CHECK-LABEL: @unordered_min_red_float_le(
-; CHECK: fcmp ule <2 x float>
+; CHECK: fcmp ogt <2 x float>
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp olt <2 x float>
@@ -779,7 +779,7 @@ for.end:
 }
 
 ; CHECK-LABEL: @inverted_unordered_min_red_float(
-; CHECK: fcmp ugt <2 x float>
+; CHECK: fcmp ole <2 x float>
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp olt <2 x float>
@@ -805,7 +805,7 @@ for.end:
 }
 
 ; CHECK-LABEL: @inverted_unordered_min_red_float_ge(
-; CHECK: fcmp uge <2 x float>
+; CHECK: fcmp olt <2 x float>
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp olt <2 x float>