Fold comparisons against a constant nan, and optimize ORD/UNORD
comparisons with a constant. This allows us to compile isnan to:
_foo:
fcmpu cr7, f1, f1
mfcr r2
rlwinm r3, r2, 0, 31, 31
blr
instead of:
LCPI1_0: ; float
.space 4
_foo:
lis r2, ha16(LCPI1_0)
lfs f0, lo16(LCPI1_0)(r2)
fcmpu cr7, f1, f0
mfcr r2
rlwinm r3, r2, 0, 31, 31
blr
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45405 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/X86/isnan.ll b/test/CodeGen/X86/isnan.ll
new file mode 100644
index 0000000..18fe29a
--- /dev/null
+++ b/test/CodeGen/X86/isnan.ll
@@ -0,0 +1,11 @@
+; RUN: llvm-as < %s | llc -march=x86 -mcpu=yonah | not grep pxor
+
+; This should not need to materialize 0.0 to evaluate the condition.
+
+define i32 @test(double %X) nounwind {
+entry:
+ %tmp6 = fcmp uno double %X, 0.000000e+00 ; <i1> [#uses=1]
+ %tmp67 = zext i1 %tmp6 to i32 ; <i32> [#uses=1]
+ ret i32 %tmp67
+}
+