[llvm] e76c95f - [InstCombine] add tests for signbit compares; NFC

Sanjay Patel via llvm-commits llvm-commits at lists.llvm.org
Mon Jan 23 15:25:25 PST 2023


Author: Sanjay Patel
Date: 2023-01-23T18:23:42-05:00
New Revision: e76c95fb40b1081438ca65be8731108fa0272a95

URL: https://github.com/llvm/llvm-project/commit/e76c95fb40b1081438ca65be8731108fa0272a95
DIFF: https://github.com/llvm/llvm-project/commit/e76c95fb40b1081438ca65be8731108fa0272a95.diff

LOG: [InstCombine] add tests for signbit compares; NFC

Added: 
    

Modified: 
    llvm/lib/Support/NativeFormatting.cpp
    llvm/test/Transforms/InstCombine/icmp-shr.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Support/NativeFormatting.cpp b/llvm/lib/Support/NativeFormatting.cpp
index 6e8137c405b80..99e705edcc698 100644
--- a/llvm/lib/Support/NativeFormatting.cpp
+++ b/llvm/lib/Support/NativeFormatting.cpp
@@ -169,11 +169,11 @@ void llvm::write_double(raw_ostream &S, double N, FloatStyle Style,
                         std::optional<size_t> Precision) {
   size_t Prec = Precision.value_or(getDefaultPrecision(Style));
 
-  if (std::isnan(N)) {
+  if (isnan(N)) {
     S << "nan";
     return;
-  } else if (std::isinf(N)) {
-    S << (std::signbit(N) ? "-INF" : "INF");
+  } else if (isinf(N)) {
+    S << (signbit(N) ? "-INF" : "INF");
     return;
   }
 

diff  --git a/llvm/test/Transforms/InstCombine/icmp-shr.ll b/llvm/test/Transforms/InstCombine/icmp-shr.ll
index cceef2e086a27..340568bafa8ef 100644
--- a/llvm/test/Transforms/InstCombine/icmp-shr.ll
+++ b/llvm/test/Transforms/InstCombine/icmp-shr.ll
@@ -1299,3 +1299,131 @@ define i1 @lshr_neg_sgt_zero(i8 %x) {
   %r = icmp sgt i8 %s, 0
   ret i1 %r
 }
+
+define i1 @exactly_one_set_signbit(i8 %x, i8 %y) {
+; CHECK-LABEL: @exactly_one_set_signbit(
+; CHECK-NEXT:    [[XSIGN:%.*]] = lshr i8 [[X:%.*]], 7
+; CHECK-NEXT:    [[YPOS:%.*]] = icmp sgt i8 [[Y:%.*]], -1
+; CHECK-NEXT:    [[YPOSZ:%.*]] = zext i1 [[YPOS]] to i8
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[XSIGN]], [[YPOSZ]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %xsign = lshr i8 %x, 7
+  %ypos = icmp sgt i8 %y, -1
+  %yposz = zext i1 %ypos to i8
+  %r = icmp eq i8 %xsign, %yposz
+  ret i1 %r
+}
+
+define i1 @exactly_one_set_signbit_use1(i8 %x, i8 %y) {
+; CHECK-LABEL: @exactly_one_set_signbit_use1(
+; CHECK-NEXT:    [[XSIGN:%.*]] = lshr i8 [[X:%.*]], 7
+; CHECK-NEXT:    call void @use(i8 [[XSIGN]])
+; CHECK-NEXT:    [[YPOS:%.*]] = icmp sgt i8 [[Y:%.*]], -1
+; CHECK-NEXT:    [[YPOSZ:%.*]] = zext i1 [[YPOS]] to i8
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[XSIGN]], [[YPOSZ]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %xsign = lshr i8 %x, 7
+  call void @use(i8 %xsign)
+  %ypos = icmp sgt i8 %y, -1
+  %yposz = zext i1 %ypos to i8
+  %r = icmp eq i8 %xsign, %yposz
+  ret i1 %r
+}
+
+define <2 x i1> @same_signbit(<2 x i8> %x, <2 x i8> %y) {
+; CHECK-LABEL: @same_signbit(
+; CHECK-NEXT:    [[XSIGN:%.*]] = lshr <2 x i8> [[X:%.*]], <i8 7, i8 7>
+; CHECK-NEXT:    [[YPOS:%.*]] = icmp sgt <2 x i8> [[Y:%.*]], <i8 -1, i8 -1>
+; CHECK-NEXT:    [[YPOSZ:%.*]] = zext <2 x i1> [[YPOS]] to <2 x i8>
+; CHECK-NEXT:    [[R:%.*]] = icmp eq <2 x i8> [[XSIGN]], [[YPOSZ]]
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %xsign = lshr <2 x i8> %x, <i8 7, i8 7>
+  %ypos = icmp sgt <2 x i8> %y, <i8 -1, i8 -1>
+  %yposz = zext <2 x i1> %ypos to <2 x i8>
+  %r = icmp eq <2 x i8> %xsign, %yposz
+  ret <2 x i1> %r
+}
+
+define i1 @same_signbit_use2(i8 %x, i8 %y) {
+; CHECK-LABEL: @same_signbit_use2(
+; CHECK-NEXT:    [[XSIGN:%.*]] = lshr i8 [[X:%.*]], 7
+; CHECK-NEXT:    [[YPOS:%.*]] = icmp sgt i8 [[Y:%.*]], -1
+; CHECK-NEXT:    [[YPOSZ:%.*]] = zext i1 [[YPOS]] to i8
+; CHECK-NEXT:    call void @use(i8 [[YPOSZ]])
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[XSIGN]], [[YPOSZ]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %xsign = lshr i8 %x, 7
+  %ypos = icmp sgt i8 %y, -1
+  %yposz = zext i1 %ypos to i8
+  call void @use(i8 %yposz)
+  %r = icmp eq i8 %xsign, %yposz
+  ret i1 %r
+}
+
+define i1 @same_signbit_use3(i8 %x, i8 %y) {
+; CHECK-LABEL: @same_signbit_use3(
+; CHECK-NEXT:    [[XSIGN:%.*]] = lshr i8 [[X:%.*]], 7
+; CHECK-NEXT:    call void @use(i8 [[XSIGN]])
+; CHECK-NEXT:    [[YPOS:%.*]] = icmp sgt i8 [[Y:%.*]], -1
+; CHECK-NEXT:    [[YPOSZ:%.*]] = zext i1 [[YPOS]] to i8
+; CHECK-NEXT:    call void @use(i8 [[YPOSZ]])
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[XSIGN]], [[YPOSZ]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %xsign = lshr i8 %x, 7
+  call void @use(i8 %xsign)
+  %ypos = icmp sgt i8 %y, -1
+  %yposz = zext i1 %ypos to i8
+  call void @use(i8 %yposz)
+  %r = icmp eq i8 %xsign, %yposz
+  ret i1 %r
+}
+
+define i1 @exactly_one_set_signbit_wrong_shamt(i8 %x, i8 %y) {
+; CHECK-LABEL: @exactly_one_set_signbit_wrong_shamt(
+; CHECK-NEXT:    [[XSIGN:%.*]] = lshr i8 [[X:%.*]], 6
+; CHECK-NEXT:    [[YPOS:%.*]] = icmp sgt i8 [[Y:%.*]], -1
+; CHECK-NEXT:    [[YPOSZ:%.*]] = zext i1 [[YPOS]] to i8
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[XSIGN]], [[YPOSZ]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %xsign = lshr i8 %x, 6
+  %ypos = icmp sgt i8 %y, -1
+  %yposz = zext i1 %ypos to i8
+  %r = icmp eq i8 %xsign, %yposz
+  ret i1 %r
+}
+
+define i1 @exactly_one_set_signbit_wrong_shr(i8 %x, i8 %y) {
+; CHECK-LABEL: @exactly_one_set_signbit_wrong_shr(
+; CHECK-NEXT:    [[XSIGN:%.*]] = ashr i8 [[X:%.*]], 7
+; CHECK-NEXT:    [[YPOS:%.*]] = icmp sgt i8 [[Y:%.*]], -1
+; CHECK-NEXT:    [[YPOSZ:%.*]] = zext i1 [[YPOS]] to i8
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[XSIGN]], [[YPOSZ]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %xsign = ashr i8 %x, 7
+  %ypos = icmp sgt i8 %y, -1
+  %yposz = zext i1 %ypos to i8
+  %r = icmp eq i8 %xsign, %yposz
+  ret i1 %r
+}
+
+define i1 @exactly_one_set_signbit_wrong_pred(i8 %x, i8 %y) {
+; CHECK-LABEL: @exactly_one_set_signbit_wrong_pred(
+; CHECK-NEXT:    [[XSIGN:%.*]] = lshr i8 [[X:%.*]], 7
+; CHECK-NEXT:    [[YPOS:%.*]] = icmp sgt i8 [[Y:%.*]], -1
+; CHECK-NEXT:    [[YPOSZ:%.*]] = zext i1 [[YPOS]] to i8
+; CHECK-NEXT:    [[R:%.*]] = icmp ugt i8 [[XSIGN]], [[YPOSZ]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %xsign = lshr i8 %x, 7
+  %ypos = icmp sgt i8 %y, -1
+  %yposz = zext i1 %ypos to i8
+  %r = icmp sgt i8 %xsign, %yposz
+  ret i1 %r
+}


        


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