[ConstantFolding] Pre-commit tests showing denormal handling during folding

[dcandler]

Summary

These tests demonstrate cases where the constant produced by folding
a floating point instruction should differ based on the denormal
handling mode set in function attributes.

[spatel]

LGTM

[simonwallis2]

I'm not sure what is the right protocol for adding review comments to a long-submitted patch.
But, whilst thinking of adding float16 tests, I noticed 4 possible inconsistencies in float32 tests.

llvm/test/Transforms/InstSimplify/constant-fold-fp-denormal.ll

562

Should #0 be #1? otherwise this test is identical to the previous test, including having the same attributes

569

576

583

[dcandler]

In D125807#4195745, @simonwallis2 wrote:

I'm not sure what is the right protocol for adding review comments to a long-submitted patch.
But, whilst thinking of adding float16 tests, I noticed 4 possible inconsistencies in float32 tests.

Yes, I remember spotting this as well. It seems I did include corrections for them in https://reviews.llvm.org/D129298 but that was ultimately abandoned.

llvm/test/Transforms/InstSimplify/constant-fold-fp-denormal.ll

+; RUN: opt -S -instsimplify < %s | FileCheck %s
+
+; Test cases for denormal handling mode when constant folding floating point
+; operations. Input and output modes are checked seperately.
+
+; ============================================================================ ;
+; fadd tests
+; Denormal operand added to normal operand produces denormal result.
+; If denormal outputs should be flushed to zero, the result should be zero.
+; If denormal inputs should be treated as zero, the result should be the
+; normal operand (a number plus zero is the same number).
+; ============================================================================ ;
+
+define float @test_float_fadd_ieee() #0 {
+; CHECK-LABEL: @test_float_fadd_ieee(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fadd float 0xB810000000000000, 0x3800000000000000
+  ret float %result
+}
+
+define float @test_float_fadd_pzero_out() #1 {
+; CHECK-LABEL: @test_float_fadd_pzero_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fadd float 0xB810000000000000, 0x3800000000000000
+  ret float %result
+}
+
+define float @test_float_fadd_psign_out() #2 {
+; CHECK-LABEL: @test_float_fadd_psign_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fadd float 0xB810000000000000, 0x3800000000000000
+  ret float %result
+}
+
+define float @test_float_fadd_pzero_in() #3 {
+; CHECK-LABEL: @test_float_fadd_pzero_in(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fadd float 0xB810000000000000, 0x3800000000000000
+  ret float %result
+}
+
+define float @test_float_fadd_psign_in() #4 {
+; CHECK-LABEL: @test_float_fadd_psign_in(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fadd float 0xB810000000000000, 0x3800000000000000
+  ret float %result
+}
+
+define float @test_float_fadd_pzero_f32_out() #5 {
+; CHECK-LABEL: @test_float_fadd_pzero_f32_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fadd float 0xB810000000000000, 0x3800000000000000
+  ret float %result
+}
+
+define double @test_double_fadd_ieee() #0 {
+; CHECK-LABEL: @test_double_fadd_ieee(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fadd double 0x8010000000000000, 0x8000000000000
+  ret double %result
+}
+
+define double @test_double_fadd_pzero_out() #1 {
+; CHECK-LABEL: @test_double_fadd_pzero_out(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fadd double 0x8010000000000000, 0x8000000000000
+  ret double %result
+}
+
+define double @test_double_fadd_psign_out() #2 {
+; CHECK-LABEL: @test_double_fadd_psign_out(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fadd double 0x8010000000000000, 0x8000000000000
+  ret double %result
+}
+
+define double @test_double_fadd_pzero_in() #3 {
+; CHECK-LABEL: @test_double_fadd_pzero_in(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fadd double 0x8010000000000000, 0x8000000000000
+  ret double %result
+}
+
+define double @test_double_fadd_psign_in() #4 {
+; CHECK-LABEL: @test_double_fadd_psign_in(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fadd double 0x8010000000000000, 0x8000000000000
+  ret double %result
+}
+
+define double @test_double_fadd_f32_ieee() #5 {
+; CHECK-LABEL: @test_double_fadd_f32_ieee(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fadd double 0x8010000000000000, 0x8000000000000
+  ret double %result
+}
+
+; ============================================================================ ;
+; fsub tests
+; Normal operand subtracted from denormal operand produces denormal result
+; If denormal outputs should be flushed to zero, the result should be zero.
+; If denormal inputs should be treated as zero, the result should be the
+; negated normal operand (zero minus the original operand).
+; ============================================================================ ;
+
+define float @test_float_fsub_ieee() #0 {
+; CHECK-LABEL: @test_float_fsub_ieee(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fsub float 0x3800000000000000, 0x3810000000000000
+  ret float %result
+}
+
+define float @test_float_fsub_pzero_out() #1 {
+; CHECK-LABEL: @test_float_fsub_pzero_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fsub float 0x3800000000000000, 0x3810000000000000
+  ret float %result
+}
+
+define float @test_float_fsub_psign_out() #2 {
+; CHECK-LABEL: @test_float_fsub_psign_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fsub float 0x3800000000000000, 0x3810000000000000
+  ret float %result
+}
+
+define float @test_float_fsub_pzero_in() #3 {
+; CHECK-LABEL: @test_float_fsub_pzero_in(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fsub float 0x3800000000000000, 0x3810000000000000
+  ret float %result
+}
+
+define float @test_float_fsub_psign_in() #4 {
+; CHECK-LABEL: @test_float_fsub_psign_in(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fsub float 0x3800000000000000, 0x3810000000000000
+  ret float %result
+}
+
+define float @test_float_fsub_pzero_f32_out() #5 {
+; CHECK-LABEL: @test_float_fsub_pzero_f32_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fsub float 0x3800000000000000, 0x3810000000000000
+  ret float %result
+}
+
+define double @test_double_fsub_ieee() #0 {
+; CHECK-LABEL: @test_double_fsub_ieee(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fsub double 0x8000000000000, 0x10000000000000
+  ret double %result
+}
+
+define double @test_double_fsub_pzero_out() #1 {
+; CHECK-LABEL: @test_double_fsub_pzero_out(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fsub double 0x8000000000000, 0x10000000000000
+  ret double %result
+}
+
+define double @test_double_fsub_psign_out() #2 {
+; CHECK-LABEL: @test_double_fsub_psign_out(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fsub double 0x8000000000000, 0x10000000000000
+  ret double %result
+}
+
+define double @test_double_fsub_pzero_in() #3 {
+; CHECK-LABEL: @test_double_fsub_pzero_in(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fsub double 0x8000000000000, 0x10000000000000
+  ret double %result
+}
+
+define double @test_double_fsub_psign_in() #4 {
+; CHECK-LABEL: @test_double_fsub_psign_in(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fsub double 0x8000000000000, 0x10000000000000
+  ret double %result
+}
+
+define double @test_double_fsub_f32_ieee() #5 {
+; CHECK-LABEL: @test_double_fsub_f32_ieee(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fsub double 0x8000000000000, 0x10000000000000
+  ret double %result
+}
+
+; ============================================================================ ;
+; fmul tests
+; Output modes are tested by multiplying the smallest normal number by 0.5,
+; producing a denormal result. If denormal outputs should be flushed to zero,
+; the result should be zero.
+; Input modes are tested by the reverse operation: taking the denormal and
+; multiplying by 2 to produce a normal number. If denormal inputs should be
+; treated as zero, the result should also be zero.
+; ============================================================================ ;
+
+define float @test_float_fmul_ieee() #0 {
+; CHECK-LABEL: @test_float_fmul_ieee(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fmul float 0x3810000000000000, -5.000000e-01
+  ret float %result
+}
+
+define float @test_float_fmul_pzero_out() #1 {
+; CHECK-LABEL: @test_float_fmul_pzero_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fmul float 0x3810000000000000, -5.000000e-01
+  ret float %result
+}
+
+define float @test_float_fmul_psign_out() #2 {
+; CHECK-LABEL: @test_float_fmul_psign_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fmul float 0x3810000000000000, -5.000000e-01
+  ret float %result
+}
+
+define float @test_float_fmul_pzero_in() #3 {
+; CHECK-LABEL: @test_float_fmul_pzero_in(
+; CHECK-NEXT:    ret float 0xB810000000000000
+; default ieee mode leaves result as a normal
+  %result = fmul float 0xB800000000000000, 2.000000e-00
+  ret float %result
+}
+
+define float @test_float_fmul_psign_in() #4 {
+; CHECK-LABEL: @test_float_fmul_psign_in(
+; CHECK-NEXT:    ret float 0xB810000000000000
+; default ieee mode leaves result as a normal
+  %result = fmul float 0xB800000000000000, 2.000000e-00
+  ret float %result
+}
+
+define float @test_float_fmul_pzero_f32_out() #1 {
+; CHECK-LABEL: @test_float_fmul_pzero_f32_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fmul float 0x3810000000000000, -5.000000e-01
+  ret float %result
+}
+
+define double @test_double_fmul_ieee() #0 {
+; CHECK-LABEL: @test_double_fmul_ieee(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fmul double 0x10000000000000, -5.000000e-01
+  ret double %result
+}
+
+define double @test_double_fmul_pzero_out() #1 {
+; CHECK-LABEL: @test_double_fmul_pzero_out(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fmul double 0x10000000000000, -5.000000e-01
+  ret double %result
+}
+
+define double @test_double_fmul_psign_out() #2 {
+; CHECK-LABEL: @test_double_fmul_psign_out(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fmul double 0x10000000000000, -5.000000e-01
+  ret double %result
+}
+
+define double @test_double_fmul_pzero_in() #3 {
+; CHECK-LABEL: @test_double_fmul_pzero_in(
+; CHECK-NEXT:    ret double 0x8010000000000000
+; default ieee mode leaves result as a normal
+  %result = fmul double 0x8008000000000000, 2.000000e-00
+  ret double %result
+}
+
+define double @test_double_fmul_psign_in() #4 {
+; CHECK-LABEL: @test_double_fmul_psign_in(
+; CHECK-NEXT:    ret double 0x8010000000000000
+; default ieee mode leaves result as a normal
+  %result = fmul double 0x8008000000000000, 2.000000e-00
+  ret double %result
+}
+
+define double @test_double_fmul_f32_ieee() #5 {
+; CHECK-LABEL: @test_double_fmul_f32_ieee(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fmul double 0x10000000000000, -5.000000e-01
+  ret double %result
+}
+
+; ============================================================================ ;
+; fdiv tests
+; Output modes are tested by dividing the smallest normal number by 2,
+; producing a denormal result. If denormal outputs should be flushed to zero,
+; the result should be zero.
+; Input modes are tested by the reverse operation: taking the denormal and
+; dividing by 0.5 to produce a normal number. If denormal inputs should be
+; treated as zero, the result should also be zero.
+; ============================================================================ ;
+
+define float @test_float_fdiv_ieee() #0 {
+; CHECK-LABEL: @test_float_fdiv_ieee(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fdiv float 0x3810000000000000, -2.000000e-00
+  ret float %result
+}
+
+define float @test_float_fdiv_pzero_out() #1 {
+; CHECK-LABEL: @test_float_fdiv_pzero_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fdiv float 0x3810000000000000, -2.000000e-00
+  ret float %result
+}
+
+define float @test_float_fdiv_psign_out() #2 {
+; CHECK-LABEL: @test_float_fdiv_psign_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fdiv float 0x3810000000000000, -2.000000e-00
+  ret float %result
+}
+
+define float @test_float_fdiv_pzero_in() #3 {
+; CHECK-LABEL: @test_float_fdiv_pzero_in(
+; CHECK-NEXT:    ret float 0xB810000000000000
+; default ieee mode leaves result as a normal
+  %result = fdiv float 0xB800000000000000, 5.000000e-01
+  ret float %result
+}
+
+define float @test_float_fdiv_psign_in() #4 {
+; CHECK-LABEL: @test_float_fdiv_psign_in(
+; CHECK-NEXT:    ret float 0xB7F0000000000000
+; default ieee mode leaves result as a normal
+  %result = fmul float 0xB800000000000000, 5.000000e-01
+  ret float %result
+}
+
+define float @test_float_fdiv_pzero_f32_out() #1 {
+; CHECK-LABEL: @test_float_fdiv_pzero_f32_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = fdiv float 0x3810000000000000, -2.000000e-00
+  ret float %result
+}
+
+define double @test_double_fdiv_ieee() #0 {
+; CHECK-LABEL: @test_double_fdiv_ieee(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fdiv double 0x10000000000000, -2.000000e-00
+  ret double %result
+}
+
+define double @test_double_fdiv_pzero_out() #1 {
+; CHECK-LABEL: @test_double_fdiv_pzero_out(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fdiv double 0x10000000000000, -2.000000e-00
+  ret double %result
+}
+
+define double @test_double_fdiv_psign_out() #2 {
+; CHECK-LABEL: @test_double_fdiv_psign_out(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fdiv double 0x10000000000000, -2.000000e-00
+  ret double %result
+}
+
+define double @test_double_fdiv_pzero_in() #3 {
+; CHECK-LABEL: @test_double_fdiv_pzero_in(
+; CHECK-NEXT:    ret double 0x8010000000000000
+; default ieee mode leaves result as a normal
+  %result = fdiv double 0x8008000000000000, 5.000000e-01
+  ret double %result
+}
+
+define double @test_double_fdiv_psign_in() #4 {
+; CHECK-LABEL: @test_double_fdiv_psign_in(
+; CHECK-NEXT:    ret double 0x8010000000000000
+; default ieee mode leaves result as a normal
+  %result = fdiv double 0x8008000000000000, 5.000000e-01
+  ret double %result
+}
+
+define double @test_double_fdiv_f32_ieee() #5 {
+; CHECK-LABEL: @test_double_fdiv_f32_ieee(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = fdiv double 0x10000000000000, -2.000000e-00
+  ret double %result
+}
+
+; ============================================================================ ;
+; frem tests
+; Output modes are tested by using two small normal numbers to produce a
+; denormal result. If denormal outputs should be flushed to zero, the result
+; should be zero.
+; Input modes are tested by calculating the remainder of a denormal number
+; and a larger normal number. If denormal inputs should be treated as zero
+; the result also becomes zero.
+; ============================================================================ ;
+
+define float @test_float_frem_ieee_out() #0 {
+; CHECK-LABEL: @test_float_frem_ieee_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = frem float 0xB818000000000000, 0x3810000000000000
+  ret float %result
+}
+
+define float @test_float_frem_pzero_out() #1 {
+; CHECK-LABEL: @test_float_frem_pzero_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = frem float 0xB818000000000000, 0x3810000000000000
+  ret float %result
+}
+
+define float @test_float_frem_psign_out() #2 {
+; CHECK-LABEL: @test_float_frem_psign_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = frem float 0xB818000000000000, 0x3810000000000000
+  ret float %result
+}
+
+define float @test_float_frem_ieee_in() #0 {
+; CHECK-LABEL: @test_float_frem_ieee_in(
+; CHECK-NEXT:    ret float 0x3800000000000000
+; default ieee mode leaves result same as input
+  %result = frem float 0x3800000000000000, 2.000000e+00
+  ret float %result
+}
+
+define float @test_float_frem_pzero_in() #3 {
+; CHECK-LABEL: @test_float_frem_pzero_in(
+; CHECK-NEXT:    ret float 0x3800000000000000
+; default ieee mode leaves result same as input
+  %result = frem float 0x3800000000000000, 2.000000e+00
+  ret float %result
+}
+
+define float @test_float_frem_psign_in() #4 {
+; CHECK-LABEL: @test_float_frem_psign_in(
+; CHECK-NEXT:    ret float 0x3800000000000000
+; default ieee mode leaves result same as input
+  %result = frem float 0x3800000000000000, 2.000000e+00
+  ret float %result
+}
+
+define float @test_float_frem_pzero_f32_out() #1 {
+; CHECK-LABEL: @test_float_frem_pzero_f32_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+; default ieee mode leaves result as a denormal
+  %result = frem float 0xB818000000000000, 0x3810000000000000
+  ret float %result
+}
+
+define double @test_double_frem_ieee_out() #0 {
+; CHECK-LABEL: @test_double_frem_ieee_out(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = frem double 0x8018000000000000, 0x10000000000000
+  ret double %result
+}
+
+define double @test_double_frem_pzero_out() #1 {
+; CHECK-LABEL: @test_double_frem_pzero_out(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = frem double 0x8018000000000000, 0x10000000000000
+  ret double %result
+}
+
+define double @test_double_frem_psign_out() #2 {
+; CHECK-LABEL: @test_double_frem_psign_out(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = frem double 0x8018000000000000, 0x10000000000000
+  ret double %result
+}
+
+define double @test_double_frem_ieee_in() #0 {
+; CHECK-LABEL: @test_double_frem_ieee_in(
+; CHECK-NEXT:    ret double 0x8000000000000
+; default ieee mode leaves result same as input
+  %result = frem double 0x8000000000000, 2.000000e+00
+  ret double %result
+}
+
+define double @test_double_frem_pzero_in() #3 {
+; CHECK-LABEL: @test_double_frem_pzero_in( 
+; CHECK-NEXT:    ret double 0x8000000000000
+; default ieee mode leaves result same as input
+  %result = frem double 0x8000000000000, 2.000000e+00
+  ret double %result
+}
+
+define double @test_double_frem_psign_in() #4 {
+; CHECK-LABEL: @test_double_frem_psign_in(
+; CHECK-NEXT:    ret double 0x8000000000000
+; default ieee mode leaves result same as input
+  %result = frem double 0x8000000000000, 2.000000e+00
+  ret double %result
+}
+
+define double @test_double_frem_f32_ieee() #5 {
+; CHECK-LABEL: @test_double_frem_f32_ieee(
+; CHECK-NEXT:    ret double 0x8008000000000000
+; default ieee mode leaves result as a denormal
+  %result = frem double 0x8018000000000000, 0x10000000000000
+  ret double %result
+}
+
+; ============================================================================ ;
+; fneg tests
+; fneg should NOT be affected by denormal handling mode
+; these tests confirm fneg results are unchanged
+; ============================================================================ ;
+
+define float @test_float_fneg_ieee() #0 {
+; CHECK-LABEL: @test_float_fneg_ieee(
+; CHECK-NEXT:    ret float 0xB800000000000000
+  %result = fneg float 0x3800000000000000
+  ret float %result
+}
+
+define float @test_float_fneg_pzero_out() #0 {
+; CHECK-LABEL: @test_float_fneg_pzero_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+  %result = fneg float 0x3800000000000000
+  ret float %result
+}
+
+define float @test_float_fneg_psign_out() #0 {
+; CHECK-LABEL: @test_float_fneg_psign_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+  %result = fneg float 0x3800000000000000
+  ret float %result
+}
+
+define float @test_float_fneg_pzero_in() #0 {
+; CHECK-LABEL: @test_float_fneg_pzero_in(
+; CHECK-NEXT:    ret float 0xB800000000000000
+  %result = fneg float 0x3800000000000000
+  ret float %result
+}
+
+define float @test_float_fneg_psign_in() #0 {
+; CHECK-LABEL: @test_float_fneg_psign_in(
+; CHECK-NEXT:    ret float 0xB800000000000000
+  %result = fneg float 0x3800000000000000
+  ret float %result
+}
+
+define float @test_float_fneg_pzero_f32_out() #5 {
+; CHECK-LABEL: @test_float_fneg_pzero_f32_out(
+; CHECK-NEXT:    ret float 0xB800000000000000
+  %result = fneg float 0x3800000000000000
+  ret float %result
+}
+
+define double @test_double_fneg_ieee() #0 {
+; CHECK-LABEL: @test_double_fneg_ieee(
+; CHECK-NEXT:    ret double 0x8008000000000000
+  %result = fneg double 0x8000000000000
+  ret double %result
+}
+
+define double @test_double_fneg_pzero_out() #1 {
+; CHECK-LABEL: @test_double_fneg_pzero_out(
+; CHECK-NEXT:    ret double 0x8008000000000000
+  %result = fneg double 0x8000000000000
+  ret double %result
+}
+
+define double @test_double_fneg_psign_out() #2 {
+; CHECK-LABEL: @test_double_fneg_psign_out(
+; CHECK-NEXT:    ret double 0x8008000000000000
+  %result = fneg double 0x8000000000000
+  ret double %result
+}
+
+define double @test_double_fneg_pzero_in() #3 {
+; CHECK-LABEL: @test_double_fneg_pzero_in(
+; CHECK-NEXT:    ret double 0x8008000000000000
+  %result = fneg double 0x8000000000000
+  ret double %result
+}
+
+define double @test_double_fneg_psign_in() #4 {
+; CHECK-LABEL: @test_double_fneg_psign_in(
+; CHECK-NEXT:    ret double 0x8008000000000000
+  %result = fneg double 0x8000000000000
+  ret double %result
+}
+
+define double @test_double_fneg_f32_ieee() #5 {
+; CHECK-LABEL: @test_double_fneg_f32_ieee(
+; CHECK-NEXT:    ret double 0x8008000000000000
+  %result = fneg double 0x8000000000000
+  ret double %result
+}
+
+attributes #0 = { nounwind "denormal-fp-math"="ieee,ieee" }
+attributes #1 = { nounwind "denormal-fp-math"="positive-zero,ieee" }
+attributes #2 = { nounwind "denormal-fp-math"="preserve-sign,ieee" }
+attributes #3 = { nounwind "denormal-fp-math"="ieee,positive-zero" }
+attributes #4 = { nounwind "denormal-fp-math"="ieee,preserve-sign" }
+attributes #5 = { nounwind "denormal-fp-math"="ieee,ieee" "denormal-fp-math-f32"="positive-zero,ieee" }