diff --git a/llvm/test/CodeGen/X86/is_fpclass.ll b/llvm/test/CodeGen/X86/is_fpclass.ll
index bc880ae7329eed..10183fb3cf3c04 100644
--- a/llvm/test/CodeGen/X86/is_fpclass.ll
+++ b/llvm/test/CodeGen/X86/is_fpclass.ll
@@ -290,6 +290,52 @@ entry:
   ret i1 %0
 }
 
+define i1 @issubnormal_f_daz(float %x) #0 {
+; CHECK-32-LABEL: issubnormal_f_daz:
+; CHECK-32:       # %bb.0: # %entry
+; CHECK-32-NEXT:    movl $2147483647, %eax # imm = 0x7FFFFFFF
+; CHECK-32-NEXT:    andl {{[0-9]+}}(%esp), %eax
+; CHECK-32-NEXT:    decl %eax
+; CHECK-32-NEXT:    cmpl $8388607, %eax # imm = 0x7FFFFF
+; CHECK-32-NEXT:    setb %al
+; CHECK-32-NEXT:    retl
+;
+; CHECK-64-LABEL: issubnormal_f_daz:
+; CHECK-64:       # %bb.0: # %entry
+; CHECK-64-NEXT:    movd %xmm0, %eax
+; CHECK-64-NEXT:    andl $2147483647, %eax # imm = 0x7FFFFFFF
+; CHECK-64-NEXT:    decl %eax
+; CHECK-64-NEXT:    cmpl $8388607, %eax # imm = 0x7FFFFF
+; CHECK-64-NEXT:    setb %al
+; CHECK-64-NEXT:    retq
+entry:
+  %0 = tail call i1 @llvm.is.fpclass.f32(float %x, i32 144)  ; 0x90 = "subnormal"
+  ret i1 %0
+}
+
+define i1 @issubnormal_f_maybe_daz(float %x) #1 {
+; CHECK-32-LABEL: issubnormal_f_maybe_daz:
+; CHECK-32:       # %bb.0: # %entry
+; CHECK-32-NEXT:    movl $2147483647, %eax # imm = 0x7FFFFFFF
+; CHECK-32-NEXT:    andl {{[0-9]+}}(%esp), %eax
+; CHECK-32-NEXT:    decl %eax
+; CHECK-32-NEXT:    cmpl $8388607, %eax # imm = 0x7FFFFF
+; CHECK-32-NEXT:    setb %al
+; CHECK-32-NEXT:    retl
+;
+; CHECK-64-LABEL: issubnormal_f_maybe_daz:
+; CHECK-64:       # %bb.0: # %entry
+; CHECK-64-NEXT:    movd %xmm0, %eax
+; CHECK-64-NEXT:    andl $2147483647, %eax # imm = 0x7FFFFFFF
+; CHECK-64-NEXT:    decl %eax
+; CHECK-64-NEXT:    cmpl $8388607, %eax # imm = 0x7FFFFF
+; CHECK-64-NEXT:    setb %al
+; CHECK-64-NEXT:    retq
+entry:
+  %0 = tail call i1 @llvm.is.fpclass.f32(float %x, i32 144)  ; 0x90 = "subnormal"
+  ret i1 %0
+}
+
 define i1 @is_plus_subnormal_f(float %x) {
 ; CHECK-32-LABEL: is_plus_subnormal_f:
 ; CHECK-32:       # %bb.0: # %entry
@@ -367,6 +413,141 @@ entry:
   ret i1 %0
 }
 
+define i1 @iszero_f_daz(float %x) #0 {
+; CHECK-32-LABEL: iszero_f_daz:
+; CHECK-32:       # %bb.0: # %entry
+; CHECK-32-NEXT:    flds {{[0-9]+}}(%esp)
+; CHECK-32-NEXT:    fldz
+; CHECK-32-NEXT:    fucompp
+; CHECK-32-NEXT:    fnstsw %ax
+; CHECK-32-NEXT:    # kill: def $ah killed $ah killed $ax
+; CHECK-32-NEXT:    sahf
+; CHECK-32-NEXT:    setnp %cl
+; CHECK-32-NEXT:    sete %al
+; CHECK-32-NEXT:    andb %cl, %al
+; CHECK-32-NEXT:    retl
+;
+; CHECK-64-LABEL: iszero_f_daz:
+; CHECK-64:       # %bb.0: # %entry
+; CHECK-64-NEXT:    xorps %xmm1, %xmm1
+; CHECK-64-NEXT:    cmpeqss %xmm0, %xmm1
+; CHECK-64-NEXT:    movd %xmm1, %eax
+; CHECK-64-NEXT:    andl $1, %eax
+; CHECK-64-NEXT:    # kill: def $al killed $al killed $eax
+; CHECK-64-NEXT:    retq
+entry:
+  %0 = tail call i1 @llvm.is.fpclass.f32(float %x, i32 96)  ; 0x60 = "zero"
+  ret i1 %0
+}
+
+define i1 @iszero_f_maybe_daz(float %x) #1 {
+; CHECK-32-LABEL: iszero_f_maybe_daz:
+; CHECK-32:       # %bb.0: # %entry
+; CHECK-32-NEXT:    flds {{[0-9]+}}(%esp)
+; CHECK-32-NEXT:    fldz
+; CHECK-32-NEXT:    fucompp
+; CHECK-32-NEXT:    fnstsw %ax
+; CHECK-32-NEXT:    # kill: def $ah killed $ah killed $ax
+; CHECK-32-NEXT:    sahf
+; CHECK-32-NEXT:    setnp %cl
+; CHECK-32-NEXT:    sete %al
+; CHECK-32-NEXT:    andb %cl, %al
+; CHECK-32-NEXT:    retl
+;
+; CHECK-64-LABEL: iszero_f_maybe_daz:
+; CHECK-64:       # %bb.0: # %entry
+; CHECK-64-NEXT:    xorps %xmm1, %xmm1
+; CHECK-64-NEXT:    cmpeqss %xmm0, %xmm1
+; CHECK-64-NEXT:    movd %xmm1, %eax
+; CHECK-64-NEXT:    andl $1, %eax
+; CHECK-64-NEXT:    # kill: def $al killed $al killed $eax
+; CHECK-64-NEXT:    retq
+entry:
+  %0 = tail call i1 @llvm.is.fpclass.f32(float %x, i32 96)  ; 0x60 = "zero"
+  ret i1 %0
+}
+
+define i1 @issubnormal_or_zero_f(float %x) {
+; CHECK-32-LABEL: issubnormal_or_zero_f:
+; CHECK-32:       # %bb.0: # %entry
+; CHECK-32-NEXT:    movl $2147483647, %eax # imm = 0x7FFFFFFF
+; CHECK-32-NEXT:    andl {{[0-9]+}}(%esp), %eax
+; CHECK-32-NEXT:    sete %cl
+; CHECK-32-NEXT:    decl %eax
+; CHECK-32-NEXT:    cmpl $8388607, %eax # imm = 0x7FFFFF
+; CHECK-32-NEXT:    setb %al
+; CHECK-32-NEXT:    orb %cl, %al
+; CHECK-32-NEXT:    retl
+;
+; CHECK-64-LABEL: issubnormal_or_zero_f:
+; CHECK-64:       # %bb.0: # %entry
+; CHECK-64-NEXT:    movd %xmm0, %eax
+; CHECK-64-NEXT:    andl $2147483647, %eax # imm = 0x7FFFFFFF
+; CHECK-64-NEXT:    sete %cl
+; CHECK-64-NEXT:    decl %eax
+; CHECK-64-NEXT:    cmpl $8388607, %eax # imm = 0x7FFFFF
+; CHECK-64-NEXT:    setb %al
+; CHECK-64-NEXT:    orb %cl, %al
+; CHECK-64-NEXT:    retq
+entry:
+  %0 = tail call i1 @llvm.is.fpclass.f32(float %x, i32 240)  ; 0xf0 = "subnormal|zero"
+  ret i1 %0
+}
+
+define i1 @issubnormal_or_zero_f_daz(float %x) #0 {
+; CHECK-32-LABEL: issubnormal_or_zero_f_daz:
+; CHECK-32:       # %bb.0: # %entry
+; CHECK-32-NEXT:    movl $2147483647, %eax # imm = 0x7FFFFFFF
+; CHECK-32-NEXT:    andl {{[0-9]+}}(%esp), %eax
+; CHECK-32-NEXT:    sete %cl
+; CHECK-32-NEXT:    decl %eax
+; CHECK-32-NEXT:    cmpl $8388607, %eax # imm = 0x7FFFFF
+; CHECK-32-NEXT:    setb %al
+; CHECK-32-NEXT:    orb %cl, %al
+; CHECK-32-NEXT:    retl
+;
+; CHECK-64-LABEL: issubnormal_or_zero_f_daz:
+; CHECK-64:       # %bb.0: # %entry
+; CHECK-64-NEXT:    movd %xmm0, %eax
+; CHECK-64-NEXT:    andl $2147483647, %eax # imm = 0x7FFFFFFF
+; CHECK-64-NEXT:    sete %cl
+; CHECK-64-NEXT:    decl %eax
+; CHECK-64-NEXT:    cmpl $8388607, %eax # imm = 0x7FFFFF
+; CHECK-64-NEXT:    setb %al
+; CHECK-64-NEXT:    orb %cl, %al
+; CHECK-64-NEXT:    retq
+entry:
+  %0 = tail call i1 @llvm.is.fpclass.f32(float %x, i32 240)  ; 0xf0 = "subnormal|zero"
+  ret i1 %0
+}
+
+define i1 @issubnormal_or_zero_f_maybe_daz(float %x) #1 {
+; CHECK-32-LABEL: issubnormal_or_zero_f_maybe_daz:
+; CHECK-32:       # %bb.0: # %entry
+; CHECK-32-NEXT:    movl $2147483647, %eax # imm = 0x7FFFFFFF
+; CHECK-32-NEXT:    andl {{[0-9]+}}(%esp), %eax
+; CHECK-32-NEXT:    sete %cl
+; CHECK-32-NEXT:    decl %eax
+; CHECK-32-NEXT:    cmpl $8388607, %eax # imm = 0x7FFFFF
+; CHECK-32-NEXT:    setb %al
+; CHECK-32-NEXT:    orb %cl, %al
+; CHECK-32-NEXT:    retl
+;
+; CHECK-64-LABEL: issubnormal_or_zero_f_maybe_daz:
+; CHECK-64:       # %bb.0: # %entry
+; CHECK-64-NEXT:    movd %xmm0, %eax
+; CHECK-64-NEXT:    andl $2147483647, %eax # imm = 0x7FFFFFFF
+; CHECK-64-NEXT:    sete %cl
+; CHECK-64-NEXT:    decl %eax
+; CHECK-64-NEXT:    cmpl $8388607, %eax # imm = 0x7FFFFF
+; CHECK-64-NEXT:    setb %al
+; CHECK-64-NEXT:    orb %cl, %al
+; CHECK-64-NEXT:    retq
+entry:
+  %0 = tail call i1 @llvm.is.fpclass.f32(float %x, i32 240)  ; 0xf0 = "subnormal|zero"
+  ret i1 %0
+}
+
 define i1 @is_plus_zero_f(float %x) {
 ; CHECK-32-LABEL: is_plus_zero_f:
 ; CHECK-32:       # %bb.0: # %entry
@@ -972,3 +1153,9 @@ declare i1 @llvm.is.fpclass.f64(double, i32)
 declare <1 x i1> @llvm.is.fpclass.v1f32(<1 x float>, i32)
 declare <2 x i1> @llvm.is.fpclass.v2f32(<2 x float>, i32)
 declare <4 x i1> @llvm.is.fpclass.v4f32(<4 x float>, i32)
+
+; Assume DAZ
+attributes #0 = { "denormal-fp-math"="ieee,preserve-sign" }
+
+; Maybe daz
+attributes #1 = { "denormal-fp-math"="ieee,dynamic" }