AMDGPU: Add baseline test for known bits of AssertNoFPClass (#167288)

Author: arsenm

llvm/test/CodeGen/AMDGPU/compute-known-bits-nofpclass.ll

@@ -0,0 +1,48 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 6
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 < %s | FileCheck %s
+
+define i32 @known_positive(float nofpclass(nan ninf nzero nsub nnorm) %signbit.zero) #0 {
+; CHECK-LABEL: known_positive:
+; CHECK:       ; %bb.0:
+; CHECK-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; CHECK-NEXT:    v_and_b32_e32 v0, 0x7fffffff, v0
+; CHECK-NEXT:    s_setpc_b64 s[30:31]
+  %cast = bitcast float %signbit.zero to i32
+  %and = and i32 %cast, 2147483647
+  ret i32 %and
+}
+
+define i32 @known_positive_maybe_nan(float nofpclass(ninf nzero nsub nnorm) %signbit.zero) #0 {
+; CHECK-LABEL: known_positive_maybe_nan:
+; CHECK:       ; %bb.0:
+; CHECK-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; CHECK-NEXT:    v_and_b32_e32 v0, 0x7fffffff, v0
+; CHECK-NEXT:    s_setpc_b64 s[30:31]
+  %cast = bitcast float %signbit.zero to i32
+  %and = and i32 %cast, 2147483647
+  ret i32 %and
+}
+
+define i32 @known_negative(float nofpclass(nan pinf pzero psub pnorm) %signbit.one) #0 {
+; CHECK-LABEL: known_negative:
+; CHECK:       ; %bb.0:
+; CHECK-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; CHECK-NEXT:    v_or_b32_e32 v0, 0x80000000, v0
+; CHECK-NEXT:    s_setpc_b64 s[30:31]
+  %cast = bitcast float %signbit.one to i32
+  %or = or i32 %cast, -2147483648
+  ret i32 %or
+}
+
+define i32 @known_negative_maybe_nan(float nofpclass(pinf pzero psub pnorm) %signbit.one) #0 {
+; CHECK-LABEL: known_negative_maybe_nan:
+; CHECK:       ; %bb.0:
+; CHECK-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; CHECK-NEXT:    v_or_b32_e32 v0, 0x80000000, v0
+; CHECK-NEXT:    s_setpc_b64 s[30:31]
+  %cast = bitcast float %signbit.one to i32
+  %or = or i32 %cast, -2147483648
+  ret i32 %or
+}
+
+attributes #0 = { nounwind }