Convert comparisons like (x == infinity) to (x >= infinity) on targets

where FCMP_OEQ is not legal and FCMP_OGE is, such as x86. 

llvm-svn: 82861

1 files changed, 76 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/X86/compare-inf.ll b/llvm/test/CodeGen/X86/compare-inf.ll
new file mode 100644
index 00000000000..2be90c9764c
--- /dev/null
+++ b/llvm/test/CodeGen/X86/compare-inf.ll
@@ -0,0 +1,76 @@
+; RUN: llc < %s -march=x86-64 | FileCheck %s
+
+; Convert oeq and une to ole/oge/ule/uge when comparing with infinity
+; and negative infinity, because those are more efficient on x86.
+
+; CHECK: oeq_inff:
+; CHECK: ucomiss
+; CHECK: jae
+define float @oeq_inff(float %x, float %y) nounwind readonly {
+  %t0 = fcmp oeq float %x, 0x7FF0000000000000
+  %t1 = select i1 %t0, float 1.0, float %y
+  ret float %t1
+}
+
+; CHECK: oeq_inf:
+; CHECK: ucomisd
+; CHECK: jae
+define double @oeq_inf(double %x, double %y) nounwind readonly {
+  %t0 = fcmp oeq double %x, 0x7FF0000000000000
+  %t1 = select i1 %t0, double 1.0, double %y
+  ret double %t1
+}
+
+; CHECK: une_inff:
+; CHECK: ucomiss
+; CHECK: jb
+define float @une_inff(float %x, float %y) nounwind readonly {
+  %t0 = fcmp une float %x, 0x7FF0000000000000
+  %t1 = select i1 %t0, float 1.0, float %y
+  ret float %t1
+}
+
+; CHECK: une_inf:
+; CHECK: ucomisd
+; CHECK: jb
+define double @une_inf(double %x, double %y) nounwind readonly {
+  %t0 = fcmp une double %x, 0x7FF0000000000000
+  %t1 = select i1 %t0, double 1.0, double %y
+  ret double %t1
+}
+
+; CHECK: oeq_neg_inff:
+; CHECK: ucomiss
+; CHECK: jae
+define float @oeq_neg_inff(float %x, float %y) nounwind readonly {
+  %t0 = fcmp oeq float %x, 0xFFF0000000000000
+  %t1 = select i1 %t0, float 1.0, float %y
+  ret float %t1
+}
+
+; CHECK: oeq_neg_inf:
+; CHECK: ucomisd
+; CHECK: jae
+define double @oeq_neg_inf(double %x, double %y) nounwind readonly {
+  %t0 = fcmp oeq double %x, 0xFFF0000000000000
+  %t1 = select i1 %t0, double 1.0, double %y
+  ret double %t1
+}
+
+; CHECK: une_neg_inff:
+; CHECK: ucomiss
+; CHECK: jb
+define float @une_neg_inff(float %x, float %y) nounwind readonly {
+  %t0 = fcmp une float %x, 0xFFF0000000000000
+  %t1 = select i1 %t0, float 1.0, float %y
+  ret float %t1
+}
+
+; CHECK: une_neg_inf:
+; CHECK: ucomisd
+; CHECK: jb
+define double @une_neg_inf(double %x, double %y) nounwind readonly {
+  %t0 = fcmp une double %x, 0xFFF0000000000000
+  %t1 = select i1 %t0, double 1.0, double %y
+  ret double %t1
+}