[AArch64][GISEL] Consider fcmp true and fcmp false in cond code selection (#86972) (#91580)

Fixes #86917

`FCMP_TRUE` and `FCMP_FALSE` were previously not considered and we ended up in an llvm_unreachable assertion.

Author: marcauberer

llvm/lib/Target/AArch64/GISel/AArch64GlobalISelUtils.cpp

@@ -147,6 +147,12 @@ void AArch64GISelUtils::changeFCMPPredToAArch64CC(
   case CmpInst::FCMP_UNE:
     CondCode = AArch64CC::NE;
     break;
+  case CmpInst::FCMP_TRUE:
+    CondCode = AArch64CC::AL;
+    break;
+  case CmpInst::FCMP_FALSE:
+    CondCode = AArch64CC::NV;
+    break;
   }
 }
 

llvm/test/CodeGen/AArch64/GlobalISel/select.mir

@@ -183,6 +183,14 @@ registers:
   - { id: 5, class: gpr }
   - { id: 6, class: gpr }
   - { id: 7, class: gpr }
+  - { id: 8, class: fpr }
+  - { id: 9, class: gpr }
+  - { id: 10, class: fpr }
+  - { id: 11, class: gpr }
+  - { id: 12, class: gpr }
+  - { id: 13, class: gpr }
+  - { id: 14, class: gpr }
+  - { id: 15, class: gpr }
 
 # CHECK:  body:
 # CHECK:    nofpexcept FCMPSrr %0, %0, implicit-def $nzcv
@@ -209,6 +217,18 @@ body:             |
     %7(s32) = G_ANYEXT %5
     $w0 = COPY %7(s32)
 
+    %8(s32) = COPY $s0
+    %9(s32) = G_FCMP floatpred(true), %8, %8
+    %12(s8) = G_TRUNC %9(s32)
+    %14(s32) = G_ANYEXT %12
+    $w0 = COPY %14(s32)
+
+    %10(s64) = COPY $d0
+    %11(s32) = G_FCMP floatpred(false), %10, %10
+    %13(s8) = G_TRUNC %11(s32)
+    %15(s32) = G_ANYEXT %13
+    $w0 = COPY %15(s32)
+
 ...
 
 ---

llvm/test/CodeGen/AArch64/neon-compare-instructions.ll

@@ -2870,6 +2870,95 @@ define <2 x i64> @fcmune2xdouble(<2 x double> %A, <2 x double> %B) {
   ret <2 x i64> %tmp4
 }
 
+define <2 x i32> @fcmal2xfloat(<2 x float> %A, <2 x float> %B) {
+; CHECK-SD-LABEL: fcmal2xfloat:
+; CHECK-SD:       // %bb.0:
+; CHECK-SD-NEXT:    movi v0.2d, #0xffffffffffffffff
+; CHECK-SD-NEXT:    ret
+;
+; CHECK-GI-LABEL: fcmal2xfloat:
+; CHECK-GI:       // %bb.0:
+; CHECK-GI-NEXT:    movi v0.2s, #1
+; CHECK-GI-NEXT:    shl v0.2s, v0.2s, #31
+; CHECK-GI-NEXT:    sshr v0.2s, v0.2s, #31
+; CHECK-GI-NEXT:    ret
+  %tmp3 = fcmp true <2 x float> %A, %B
+  %tmp4 = sext <2 x i1> %tmp3 to <2 x i32>
+  ret <2 x i32> %tmp4
+}
+
+define <4 x i32> @fcmal4xfloat(<4 x float> %A, <4 x float> %B) {
+; CHECK-SD-LABEL: fcmal4xfloat:
+; CHECK-SD:       // %bb.0:
+; CHECK-SD-NEXT:    movi v0.2d, #0xffffffffffffffff
+; CHECK-SD-NEXT:    ret
+;
+; CHECK-GI-LABEL: fcmal4xfloat:
+; CHECK-GI:       // %bb.0:
+; CHECK-GI-NEXT:    movi v0.2s, #1
+; CHECK-GI-NEXT:    mov v0.d[1], v0.d[0]
+; CHECK-GI-NEXT:    shl v0.4s, v0.4s, #31
+; CHECK-GI-NEXT:    sshr v0.4s, v0.4s, #31
+; CHECK-GI-NEXT:    ret
+  %tmp3 = fcmp true <4 x float> %A, %B
+  %tmp4 = sext <4 x i1> %tmp3 to <4 x i32>
+  ret <4 x i32> %tmp4
+}
+define <2 x i64> @fcmal2xdouble(<2 x double> %A, <2 x double> %B) {
+; CHECK-SD-LABEL: fcmal2xdouble:
+; CHECK-SD:       // %bb.0:
+; CHECK-SD-NEXT:    movi v0.2d, #0xffffffffffffffff
+; CHECK-SD-NEXT:    ret
+;
+; CHECK-GI-LABEL: fcmal2xdouble:
+; CHECK-GI:       // %bb.0:
+; CHECK-GI-NEXT:    adrp x8, .LCPI221_0
+; CHECK-GI-NEXT:    ldr q0, [x8, :lo12:.LCPI221_0]
+; CHECK-GI-NEXT:    shl v0.2d, v0.2d, #63
+; CHECK-GI-NEXT:    sshr v0.2d, v0.2d, #63
+; CHECK-GI-NEXT:    ret
+  %tmp3 = fcmp true <2 x double> %A, %B
+  %tmp4 = sext <2 x i1> %tmp3 to <2 x i64>
+  ret <2 x i64> %tmp4
+}
+
+define <2 x i32> @fcmnv2xfloat(<2 x float> %A, <2 x float> %B) {
+; CHECK-LABEL: fcmnv2xfloat:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    movi v0.2d, #0000000000000000
+; CHECK-NEXT:    ret
+  %tmp3 = fcmp false <2 x float> %A, %B
+  %tmp4 = sext <2 x i1> %tmp3 to <2 x i32>
+  ret <2 x i32> %tmp4
+}
+
+define <4 x i32> @fcmnv4xfloat(<4 x float> %A, <4 x float> %B) {
+; CHECK-SD-LABEL: fcmnv4xfloat:
+; CHECK-SD:       // %bb.0:
+; CHECK-SD-NEXT:    movi v0.2d, #0000000000000000
+; CHECK-SD-NEXT:    ret
+;
+; CHECK-GI-LABEL: fcmnv4xfloat:
+; CHECK-GI:       // %bb.0:
+; CHECK-GI-NEXT:    movi v0.2d, #0000000000000000
+; CHECK-GI-NEXT:    mov v0.d[1], v0.d[0]
+; CHECK-GI-NEXT:    shl v0.4s, v0.4s, #31
+; CHECK-GI-NEXT:    sshr v0.4s, v0.4s, #31
+; CHECK-GI-NEXT:    ret
+  %tmp3 = fcmp false <4 x float> %A, %B
+  %tmp4 = sext <4 x i1> %tmp3 to <4 x i32>
+  ret <4 x i32> %tmp4
+}
+define <2 x i64> @fcmnv2xdouble(<2 x double> %A, <2 x double> %B) {
+; CHECK-LABEL: fcmnv2xdouble:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    movi v0.2d, #0000000000000000
+; CHECK-NEXT:    ret
+  %tmp3 = fcmp false <2 x double> %A, %B
+  %tmp4 = sext <2 x i1> %tmp3 to <2 x i64>
+  ret <2 x i64> %tmp4
+}
+
 define <2 x i32> @fcmoeqz2xfloat(<2 x float> %A) {
 ; CHECK-LABEL: fcmoeqz2xfloat:
 ; CHECK:       // %bb.0: