[AArch64][GlobalISel] Add commute_constant_to_rhs to post legalizer combiners (llvm#81103)

This helps the fp reductions, moving the constant operands to the RHS
which in turn helps simplify away fadd -0.0 and fmul 1.0.

Author: davemgreen

llvm/lib/Target/AArch64/AArch64Combine.td

@@ -288,5 +288,6 @@ def AArch64PostLegalizerCombiner
                         constant_fold_binops, identity_combines,
                         ptr_add_immed_chain, overlapping_and,
                         split_store_zero_128, undef_combines,
-                        select_to_minmax, or_to_bsp]> {
+                        select_to_minmax, or_to_bsp,
+                        commute_constant_to_rhs]> {
 }

llvm/test/CodeGen/AArch64/GlobalISel/arm64-atomic.ll

@@ -2146,8 +2146,7 @@ define i8 @atomicrmw_and_i8(ptr %ptr, i8 %rhs) {
 ; CHECK-OUTLINE-O1-NEXT:    .cfi_offset w30, -8
 ; CHECK-OUTLINE-O1-NEXT:    .cfi_offset w29, -16
 ; CHECK-OUTLINE-O1-NEXT:    mov x2, x0
-; CHECK-OUTLINE-O1-NEXT:    mov w8, #-1 ; =0xffffffff
-; CHECK-OUTLINE-O1-NEXT:    eor w0, w8, w1
+; CHECK-OUTLINE-O1-NEXT:    mvn w0, w1
 ; CHECK-OUTLINE-O1-NEXT:    mov x1, x2
 ; CHECK-OUTLINE-O1-NEXT:    bl ___aarch64_ldclr1_rel
 ; CHECK-OUTLINE-O1-NEXT:    ldp x29, x30, [sp], #16 ; 16-byte Folded Reload
@@ -3202,8 +3201,7 @@ define i16 @atomicrmw_and_i16(ptr %ptr, i16 %rhs) {
 ; CHECK-OUTLINE-O1-NEXT:    .cfi_offset w30, -8
 ; CHECK-OUTLINE-O1-NEXT:    .cfi_offset w29, -16
 ; CHECK-OUTLINE-O1-NEXT:    mov x2, x0
-; CHECK-OUTLINE-O1-NEXT:    mov w8, #-1 ; =0xffffffff
-; CHECK-OUTLINE-O1-NEXT:    eor w0, w8, w1
+; CHECK-OUTLINE-O1-NEXT:    mvn w0, w1
 ; CHECK-OUTLINE-O1-NEXT:    mov x1, x2
 ; CHECK-OUTLINE-O1-NEXT:    bl ___aarch64_ldclr2_rel
 ; CHECK-OUTLINE-O1-NEXT:    ldp x29, x30, [sp], #16 ; 16-byte Folded Reload
@@ -4255,8 +4253,7 @@ define i32 @atomicrmw_and_i32(ptr %ptr, i32 %rhs) {
 ; CHECK-OUTLINE-O1-NEXT:    .cfi_offset w30, -8
 ; CHECK-OUTLINE-O1-NEXT:    .cfi_offset w29, -16
 ; CHECK-OUTLINE-O1-NEXT:    mov x2, x0
-; CHECK-OUTLINE-O1-NEXT:    mov w8, #-1 ; =0xffffffff
-; CHECK-OUTLINE-O1-NEXT:    eor w0, w8, w1
+; CHECK-OUTLINE-O1-NEXT:    mvn w0, w1
 ; CHECK-OUTLINE-O1-NEXT:    mov x1, x2
 ; CHECK-OUTLINE-O1-NEXT:    bl ___aarch64_ldclr4_rel
 ; CHECK-OUTLINE-O1-NEXT:    ldp x29, x30, [sp], #16 ; 16-byte Folded Reload
@@ -5276,8 +5273,7 @@ define i64 @atomicrmw_and_i64(ptr %ptr, i64 %rhs) {
 ; CHECK-OUTLINE-O1-NEXT:    .cfi_offset w30, -8
 ; CHECK-OUTLINE-O1-NEXT:    .cfi_offset w29, -16
 ; CHECK-OUTLINE-O1-NEXT:    mov x2, x0
-; CHECK-OUTLINE-O1-NEXT:    mov x8, #-1 ; =0xffffffffffffffff
-; CHECK-OUTLINE-O1-NEXT:    eor x0, x8, x1
+; CHECK-OUTLINE-O1-NEXT:    mvn x0, x1
 ; CHECK-OUTLINE-O1-NEXT:    mov x1, x2
 ; CHECK-OUTLINE-O1-NEXT:    bl ___aarch64_ldclr8_rel
 ; CHECK-OUTLINE-O1-NEXT:    ldp x29, x30, [sp], #16 ; 16-byte Folded Reload

llvm/test/CodeGen/AArch64/vecreduce-fadd-strict.ll

@@ -13,11 +13,7 @@ define float @add_HalfS(<2 x float> %bin.rdx)  {
 ;
 ; CHECK-GI-LABEL: add_HalfS:
 ; CHECK-GI:       // %bb.0:
-; CHECK-GI-NEXT:    movi v1.2s, #128, lsl #24
-; CHECK-GI-NEXT:    // kill: def $d0 killed $d0 def $q0
-; CHECK-GI-NEXT:    mov s2, v0.s[1]
-; CHECK-GI-NEXT:    fadd s0, s1, s0
-; CHECK-GI-NEXT:    fadd s0, s0, s2
+; CHECK-GI-NEXT:    faddp s0, v0.2s
 ; CHECK-GI-NEXT:    ret
   %r = call float @llvm.vector.reduce.fadd.f32.v2f32(float -0.0, <2 x float> %bin.rdx)
   ret float %r
@@ -82,15 +78,12 @@ define half @add_HalfH(<4 x half> %bin.rdx)  {
 ;
 ; CHECK-GI-FP16-LABEL: add_HalfH:
 ; CHECK-GI-FP16:       // %bb.0:
-; CHECK-GI-FP16-NEXT:    adrp x8, .LCPI1_0
 ; CHECK-GI-FP16-NEXT:    // kill: def $d0 killed $d0 def $q0
-; CHECK-GI-FP16-NEXT:    mov h2, v0.h[1]
-; CHECK-GI-FP16-NEXT:    mov h3, v0.h[2]
-; CHECK-GI-FP16-NEXT:    ldr h1, [x8, :lo12:.LCPI1_0]
-; CHECK-GI-FP16-NEXT:    fadd h1, h1, h0
+; CHECK-GI-FP16-NEXT:    mov h1, v0.h[1]
+; CHECK-GI-FP16-NEXT:    mov h2, v0.h[2]
+; CHECK-GI-FP16-NEXT:    fadd h1, h0, h1
 ; CHECK-GI-FP16-NEXT:    mov h0, v0.h[3]
 ; CHECK-GI-FP16-NEXT:    fadd h1, h1, h2
-; CHECK-GI-FP16-NEXT:    fadd h1, h1, h3
 ; CHECK-GI-FP16-NEXT:    fadd h0, h1, h0
 ; CHECK-GI-FP16-NEXT:    ret
   %r = call half @llvm.vector.reduce.fadd.f16.v4f16(half -0.0, <4 x half> %bin.rdx)
@@ -202,67 +195,42 @@ define half @add_H(<8 x half> %bin.rdx)  {
 ;
 ; CHECK-GI-FP16-LABEL: add_H:
 ; CHECK-GI-FP16:       // %bb.0:
-; CHECK-GI-FP16-NEXT:    adrp x8, .LCPI2_0
-; CHECK-GI-FP16-NEXT:    mov h2, v0.h[1]
-; CHECK-GI-FP16-NEXT:    mov h3, v0.h[2]
-; CHECK-GI-FP16-NEXT:    ldr h1, [x8, :lo12:.LCPI2_0]
-; CHECK-GI-FP16-NEXT:    fadd h1, h1, h0
-; CHECK-GI-FP16-NEXT:    fadd h1, h1, h2
-; CHECK-GI-FP16-NEXT:    mov h2, v0.h[3]
+; CHECK-GI-FP16-NEXT:    mov h1, v0.h[2]
+; CHECK-GI-FP16-NEXT:    faddp h2, v0.2h
+; CHECK-GI-FP16-NEXT:    mov h3, v0.h[3]
+; CHECK-GI-FP16-NEXT:    fadd h1, h2, h1
+; CHECK-GI-FP16-NEXT:    mov h2, v0.h[4]
 ; CHECK-GI-FP16-NEXT:    fadd h1, h1, h3
-; CHECK-GI-FP16-NEXT:    mov h3, v0.h[4]
+; CHECK-GI-FP16-NEXT:    mov h3, v0.h[5]
 ; CHECK-GI-FP16-NEXT:    fadd h1, h1, h2
-; CHECK-GI-FP16-NEXT:    mov h2, v0.h[5]
-; CHECK-GI-FP16-NEXT:    fadd h1, h1, h3
-; CHECK-GI-FP16-NEXT:    mov h3, v0.h[6]
+; CHECK-GI-FP16-NEXT:    mov h2, v0.h[6]
 ; CHECK-GI-FP16-NEXT:    mov h0, v0.h[7]
-; CHECK-GI-FP16-NEXT:    fadd h1, h1, h2
 ; CHECK-GI-FP16-NEXT:    fadd h1, h1, h3
+; CHECK-GI-FP16-NEXT:    fadd h1, h1, h2
 ; CHECK-GI-FP16-NEXT:    fadd h0, h1, h0
 ; CHECK-GI-FP16-NEXT:    ret
   %r = call half @llvm.vector.reduce.fadd.f16.v8f16(half -0.0, <8 x half> %bin.rdx)
   ret half %r
 }
 
 define float @add_S(<4 x float> %bin.rdx)  {
-; CHECK-SD-LABEL: add_S:
-; CHECK-SD:       // %bb.0:
-; CHECK-SD-NEXT:    mov s1, v0.s[2]
-; CHECK-SD-NEXT:    faddp s2, v0.2s
-; CHECK-SD-NEXT:    mov s0, v0.s[3]
-; CHECK-SD-NEXT:    fadd s1, s2, s1
-; CHECK-SD-NEXT:    fadd s0, s1, s0
-; CHECK-SD-NEXT:    ret
-;
-; CHECK-GI-LABEL: add_S:
-; CHECK-GI:       // %bb.0:
-; CHECK-GI-NEXT:    movi v1.2s, #128, lsl #24
-; CHECK-GI-NEXT:    mov s2, v0.s[1]
-; CHECK-GI-NEXT:    mov s3, v0.s[2]
-; CHECK-GI-NEXT:    fadd s1, s1, s0
-; CHECK-GI-NEXT:    mov s0, v0.s[3]
-; CHECK-GI-NEXT:    fadd s1, s1, s2
-; CHECK-GI-NEXT:    fadd s1, s1, s3
-; CHECK-GI-NEXT:    fadd s0, s1, s0
-; CHECK-GI-NEXT:    ret
+; CHECK-LABEL: add_S:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    mov s1, v0.s[2]
+; CHECK-NEXT:    faddp s2, v0.2s
+; CHECK-NEXT:    mov s0, v0.s[3]
+; CHECK-NEXT:    fadd s1, s2, s1
+; CHECK-NEXT:    fadd s0, s1, s0
+; CHECK-NEXT:    ret
   %r = call float @llvm.vector.reduce.fadd.f32.v4f32(float -0.0, <4 x float> %bin.rdx)
   ret float %r
 }
 
 define double @add_D(<2 x double> %bin.rdx)  {
-; CHECK-SD-LABEL: add_D:
-; CHECK-SD:       // %bb.0:
-; CHECK-SD-NEXT:    faddp d0, v0.2d
-; CHECK-SD-NEXT:    ret
-;
-; CHECK-GI-LABEL: add_D:
-; CHECK-GI:       // %bb.0:
-; CHECK-GI-NEXT:    mov x8, #-9223372036854775808 // =0x8000000000000000
-; CHECK-GI-NEXT:    mov d2, v0.d[1]
-; CHECK-GI-NEXT:    fmov d1, x8
-; CHECK-GI-NEXT:    fadd d0, d1, d0
-; CHECK-GI-NEXT:    fadd d0, d0, d2
-; CHECK-GI-NEXT:    ret
+; CHECK-LABEL: add_D:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    faddp d0, v0.2d
+; CHECK-NEXT:    ret
   %r = call double @llvm.vector.reduce.fadd.f64.v2f64(double -0.0, <2 x double> %bin.rdx)
   ret double %r
 }
@@ -464,23 +432,19 @@ define half @add_2H(<16 x half> %bin.rdx)  {
 ;
 ; CHECK-GI-FP16-LABEL: add_2H:
 ; CHECK-GI-FP16:       // %bb.0:
-; CHECK-GI-FP16-NEXT:    adrp x8, .LCPI5_0
-; CHECK-GI-FP16-NEXT:    mov h3, v0.h[1]
-; CHECK-GI-FP16-NEXT:    mov h4, v0.h[2]
-; CHECK-GI-FP16-NEXT:    ldr h2, [x8, :lo12:.LCPI5_0]
-; CHECK-GI-FP16-NEXT:    fadd h2, h2, h0
-; CHECK-GI-FP16-NEXT:    fadd h2, h2, h3
-; CHECK-GI-FP16-NEXT:    mov h3, v0.h[3]
+; CHECK-GI-FP16-NEXT:    mov h2, v0.h[2]
+; CHECK-GI-FP16-NEXT:    faddp h3, v0.2h
+; CHECK-GI-FP16-NEXT:    mov h4, v0.h[3]
+; CHECK-GI-FP16-NEXT:    fadd h2, h3, h2
+; CHECK-GI-FP16-NEXT:    mov h3, v0.h[4]
 ; CHECK-GI-FP16-NEXT:    fadd h2, h2, h4
-; CHECK-GI-FP16-NEXT:    mov h4, v0.h[4]
+; CHECK-GI-FP16-NEXT:    mov h4, v0.h[5]
 ; CHECK-GI-FP16-NEXT:    fadd h2, h2, h3
-; CHECK-GI-FP16-NEXT:    mov h3, v0.h[5]
-; CHECK-GI-FP16-NEXT:    fadd h2, h2, h4
-; CHECK-GI-FP16-NEXT:    mov h4, v0.h[6]
+; CHECK-GI-FP16-NEXT:    mov h3, v0.h[6]
 ; CHECK-GI-FP16-NEXT:    mov h0, v0.h[7]
+; CHECK-GI-FP16-NEXT:    fadd h2, h2, h4
 ; CHECK-GI-FP16-NEXT:    fadd h2, h2, h3
 ; CHECK-GI-FP16-NEXT:    mov h3, v1.h[2]
-; CHECK-GI-FP16-NEXT:    fadd h2, h2, h4
 ; CHECK-GI-FP16-NEXT:    fadd h0, h2, h0
 ; CHECK-GI-FP16-NEXT:    mov h2, v1.h[1]
 ; CHECK-GI-FP16-NEXT:    fadd h0, h0, h1
@@ -502,95 +466,51 @@ define half @add_2H(<16 x half> %bin.rdx)  {
 }
 
 define float @add_2S(<8 x float> %bin.rdx)  {
-; CHECK-SD-LABEL: add_2S:
-; CHECK-SD:       // %bb.0:
-; CHECK-SD-NEXT:    mov s2, v0.s[2]
-; CHECK-SD-NEXT:    faddp s3, v0.2s
-; CHECK-SD-NEXT:    mov s0, v0.s[3]
-; CHECK-SD-NEXT:    fadd s2, s3, s2
-; CHECK-SD-NEXT:    mov s3, v1.s[2]
-; CHECK-SD-NEXT:    fadd s0, s2, s0
-; CHECK-SD-NEXT:    mov s2, v1.s[1]
-; CHECK-SD-NEXT:    fadd s0, s0, s1
-; CHECK-SD-NEXT:    mov s1, v1.s[3]
-; CHECK-SD-NEXT:    fadd s0, s0, s2
-; CHECK-SD-NEXT:    fadd s0, s0, s3
-; CHECK-SD-NEXT:    fadd s0, s0, s1
-; CHECK-SD-NEXT:    ret
-;
-; CHECK-GI-LABEL: add_2S:
-; CHECK-GI:       // %bb.0:
-; CHECK-GI-NEXT:    movi v2.2s, #128, lsl #24
-; CHECK-GI-NEXT:    mov s3, v0.s[1]
-; CHECK-GI-NEXT:    mov s4, v0.s[2]
-; CHECK-GI-NEXT:    fadd s2, s2, s0
-; CHECK-GI-NEXT:    mov s0, v0.s[3]
-; CHECK-GI-NEXT:    fadd s2, s2, s3
-; CHECK-GI-NEXT:    mov s3, v1.s[2]
-; CHECK-GI-NEXT:    fadd s2, s2, s4
-; CHECK-GI-NEXT:    fadd s0, s2, s0
-; CHECK-GI-NEXT:    mov s2, v1.s[1]
-; CHECK-GI-NEXT:    fadd s0, s0, s1
-; CHECK-GI-NEXT:    mov s1, v1.s[3]
-; CHECK-GI-NEXT:    fadd s0, s0, s2
-; CHECK-GI-NEXT:    fadd s0, s0, s3
-; CHECK-GI-NEXT:    fadd s0, s0, s1
-; CHECK-GI-NEXT:    ret
+; CHECK-LABEL: add_2S:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    mov s2, v0.s[2]
+; CHECK-NEXT:    faddp s3, v0.2s
+; CHECK-NEXT:    mov s0, v0.s[3]
+; CHECK-NEXT:    fadd s2, s3, s2
+; CHECK-NEXT:    mov s3, v1.s[2]
+; CHECK-NEXT:    fadd s0, s2, s0
+; CHECK-NEXT:    mov s2, v1.s[1]
+; CHECK-NEXT:    fadd s0, s0, s1
+; CHECK-NEXT:    mov s1, v1.s[3]
+; CHECK-NEXT:    fadd s0, s0, s2
+; CHECK-NEXT:    fadd s0, s0, s3
+; CHECK-NEXT:    fadd s0, s0, s1
+; CHECK-NEXT:    ret
   %r = call float @llvm.vector.reduce.fadd.f32.v8f32(float -0.0, <8 x float> %bin.rdx)
   ret float %r
 }
 
 define double @add_2D(<4 x double> %bin.rdx)  {
-; CHECK-SD-LABEL: add_2D:
-; CHECK-SD:       // %bb.0:
-; CHECK-SD-NEXT:    faddp d0, v0.2d
-; CHECK-SD-NEXT:    mov d2, v1.d[1]
-; CHECK-SD-NEXT:    fadd d0, d0, d1
-; CHECK-SD-NEXT:    fadd d0, d0, d2
-; CHECK-SD-NEXT:    ret
-;
-; CHECK-GI-LABEL: add_2D:
-; CHECK-GI:       // %bb.0:
-; CHECK-GI-NEXT:    mov x8, #-9223372036854775808 // =0x8000000000000000
-; CHECK-GI-NEXT:    mov d3, v0.d[1]
-; CHECK-GI-NEXT:    fmov d2, x8
-; CHECK-GI-NEXT:    fadd d0, d2, d0
-; CHECK-GI-NEXT:    mov d2, v1.d[1]
-; CHECK-GI-NEXT:    fadd d0, d0, d3
-; CHECK-GI-NEXT:    fadd d0, d0, d1
-; CHECK-GI-NEXT:    fadd d0, d0, d2
-; CHECK-GI-NEXT:    ret
+; CHECK-LABEL: add_2D:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    faddp d0, v0.2d
+; CHECK-NEXT:    mov d2, v1.d[1]
+; CHECK-NEXT:    fadd d0, d0, d1
+; CHECK-NEXT:    fadd d0, d0, d2
+; CHECK-NEXT:    ret
   %r = call double @llvm.vector.reduce.fadd.f64.v4f64(double -0.0, <4 x double> %bin.rdx)
   ret double %r
 }
 
 ; Added at least one test where the start value is not -0.0.
 define float @add_S_init_42(<4 x float> %bin.rdx)  {
-; CHECK-SD-LABEL: add_S_init_42:
-; CHECK-SD:       // %bb.0:
-; CHECK-SD-NEXT:    mov w8, #1109917696 // =0x42280000
-; CHECK-SD-NEXT:    mov s2, v0.s[1]
-; CHECK-SD-NEXT:    mov s3, v0.s[2]
-; CHECK-SD-NEXT:    fmov s1, w8
-; CHECK-SD-NEXT:    fadd s1, s0, s1
-; CHECK-SD-NEXT:    mov s0, v0.s[3]
-; CHECK-SD-NEXT:    fadd s1, s1, s2
-; CHECK-SD-NEXT:    fadd s1, s1, s3
-; CHECK-SD-NEXT:    fadd s0, s1, s0
-; CHECK-SD-NEXT:    ret
-;
-; CHECK-GI-LABEL: add_S_init_42:
-; CHECK-GI:       // %bb.0:
-; CHECK-GI-NEXT:    mov w8, #1109917696 // =0x42280000
-; CHECK-GI-NEXT:    mov s2, v0.s[1]
-; CHECK-GI-NEXT:    mov s3, v0.s[2]
-; CHECK-GI-NEXT:    fmov s1, w8
-; CHECK-GI-NEXT:    fadd s1, s1, s0
-; CHECK-GI-NEXT:    mov s0, v0.s[3]
-; CHECK-GI-NEXT:    fadd s1, s1, s2
-; CHECK-GI-NEXT:    fadd s1, s1, s3
-; CHECK-GI-NEXT:    fadd s0, s1, s0
-; CHECK-GI-NEXT:    ret
+; CHECK-LABEL: add_S_init_42:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    mov w8, #1109917696 // =0x42280000
+; CHECK-NEXT:    mov s2, v0.s[1]
+; CHECK-NEXT:    mov s3, v0.s[2]
+; CHECK-NEXT:    fmov s1, w8
+; CHECK-NEXT:    fadd s1, s0, s1
+; CHECK-NEXT:    mov s0, v0.s[3]
+; CHECK-NEXT:    fadd s1, s1, s2
+; CHECK-NEXT:    fadd s1, s1, s3
+; CHECK-NEXT:    fadd s0, s1, s0
+; CHECK-NEXT:    ret
   %r = call float @llvm.vector.reduce.fadd.f32.v4f32(float 42.0, <4 x float> %bin.rdx)
   ret float %r
 }
@@ -604,5 +524,3 @@ declare float @llvm.vector.reduce.fadd.f32.v4f32(float, <4 x float>)
 declare float @llvm.vector.reduce.fadd.f32.v8f32(float, <8 x float>)
 declare double @llvm.vector.reduce.fadd.f64.v2f64(double, <2 x double>)
 declare double @llvm.vector.reduce.fadd.f64.v4f64(double, <4 x double>)
-;; NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
-; CHECK: {{.*}}