diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -144,6 +144,13 @@ Arm and AArch64 Support in Clang -------------------------------- +* The hard-float ABI is now available in Armv8.1-M configurations that + have integer MVE instructions (and therefore have FP registers) but + no scalar or vector floating point computation. Previously, trying + to select the hard-float ABI on such a target (via + ``-mfloat-abi=hard`` or a triple ending in ``hf``) would silently + use the soft-float ABI instead. + Floating Point Support in Clang ------------------------------- diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst --- a/llvm/docs/ReleaseNotes.rst +++ b/llvm/docs/ReleaseNotes.rst @@ -71,6 +71,10 @@ Changes to the ARM Backend -------------------------- +- The hard-float ABI is now available in Armv8.1-M configurations that + have integer MVE instructions (and therefore have FP registers) but + no scalar or vector floating point computation. + Changes to the AVR Backend -------------------------- diff --git a/llvm/lib/Target/ARM/ARMFastISel.cpp b/llvm/lib/Target/ARM/ARMFastISel.cpp --- a/llvm/lib/Target/ARM/ARMFastISel.cpp +++ b/llvm/lib/Target/ARM/ARMFastISel.cpp @@ -1842,7 +1842,7 @@ case CallingConv::CXX_FAST_TLS: // Use target triple & subtarget features to do actual dispatch. if (Subtarget->isAAPCS_ABI()) { - if (Subtarget->hasVFP2Base() && + if (Subtarget->hasFPRegs() && TM.Options.FloatABIType == FloatABI::Hard && !isVarArg) return (Return ? RetCC_ARM_AAPCS_VFP: CC_ARM_AAPCS_VFP); else diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp --- a/llvm/lib/Target/ARM/ARMISelLowering.cpp +++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp @@ -2081,7 +2081,7 @@ case CallingConv::Tail: if (!Subtarget->isAAPCS_ABI()) return CallingConv::ARM_APCS; - else if (Subtarget->hasVFP2Base() && !Subtarget->isThumb1Only() && + else if (Subtarget->hasFPRegs() && !Subtarget->isThumb1Only() && getTargetMachine().Options.FloatABIType == FloatABI::Hard && !isVarArg) return CallingConv::ARM_AAPCS_VFP; diff --git a/llvm/test/CodeGen/Thumb2/float-ops.ll b/llvm/test/CodeGen/Thumb2/float-ops.ll --- a/llvm/test/CodeGen/Thumb2/float-ops.ll +++ b/llvm/test/CodeGen/Thumb2/float-ops.ll @@ -83,7 +83,7 @@ define float @rem_f(float %a, float %b) { entry: ; CHECK-LABEL: rem_f: -; NONE: bl fmodf +; NONE: {{b|bl}} fmodf ; HARD: b fmodf %0 = frem float %a, %b ret float %0 @@ -92,16 +92,23 @@ define double @rem_d(double %a, double %b) { entry: ; CHECK-LABEL: rem_d: -; NONE: bl fmod +; NONE: {{b|bl}} fmod ; HARD: b fmod %0 = frem double %a, %b ret double %0 } +; In the ONLYREGS case (where we have integer MVE but no floating +; point), we still expect the hard float ABI, because we asked for it +; in the triple, and since the FP registers exist, it's possible to +; use them to pass arguments. So the generated code should load the +; return value into s0, not r0. Similarly for the other load and store +; tests. define float @load_f(ptr %a) { entry: ; CHECK-LABEL: load_f: -; NONE: ldr r0, [r0] +; NOREGS: ldr r0, [r0] +; ONLYREGS: vldr s0, [r0] ; HARD: vldr s0, [r0] %0 = load float, ptr %a, align 4 ret float %0 @@ -120,7 +127,8 @@ define void @store_f(ptr %a, float %b) { entry: ; CHECK-LABEL: store_f: -; NONE: str r1, [r0] +; NOREGS: str r1, [r0] +; ONLYREGS: vstr s0, [r0] ; HARD: vstr s0, [r0] store float %b, ptr %a, align 4 ret void @@ -130,7 +138,7 @@ entry: ; CHECK-LABEL: store_d: ; NOREGS: strd r2, r3, [r0] -; ONLYREGS: strd r2, r3, [r0] +; ONLYREGS: vstr d0, [r0] ; HARD: vstr d0, [r0] store double %b, ptr %a, align 8 ret void @@ -230,7 +238,8 @@ define float @bitcast_i_to_f(i32 %a) { ; CHECK-LABEL: bitcast_i_to_f: -; NONE-NOT: mov +; NOREGS-NOT: mov +; ONLYREGS: vmov s0, r0 ; HARD: vmov s0, r0 %1 = bitcast i32 %a to float ret float %1 @@ -238,15 +247,17 @@ define double @bitcast_i_to_d(i64 %a) { ; CHECK-LABEL: bitcast_i_to_d: -; NONE-NOT: mov -; HARD: vmov d0, r0, r1 - %1 = bitcast i64 %a to double +; NOREGS-NOT: mov +; ONLYREGS: vmov d0, r0, r1 +; HARD: vmov d0, r0, r1 + %1 = bitcast i64 %a to double ret double %1 } define i32 @bitcast_f_to_i(float %a) { ; CHECK-LABEL: bitcast_f_to_i: -; NONE-NOT: mov +; NOREGS-NOT: mov +; ONLYREGS: vmov r0, s0 ; HARD: vmov r0, s0 %1 = bitcast float %a to i32 ret i32 %1 @@ -254,7 +265,8 @@ define i64 @bitcast_d_to_i(double %a) { ; CHECK-LABEL: bitcast_d_to_i: -; NONE-NOT: mov +; NOREGS-NOT: mov +; ONLYREGS: vmov r0, r1, d0 ; HARD: vmov r0, r1, d0 %1 = bitcast double %a to i64 ret i64 %1 @@ -264,8 +276,8 @@ ; CHECK-LABEL: select_f: ; NOREGS: lsls r2, r2, #31 ; NOREGS: moveq r0, r1 -; ONLYREGS: lsls r2, r2, #31 -; ONLYREGS: vmovne.f32 s2, s0 +; ONLYREGS: lsls r0, r0, #31 +; ONLYREGS: vmovne.f32 s1, s0 ; HARD: lsls r0, r0, #31 ; VFP4-ALL: vmovne.f32 s1, s0 ; VFP4-ALL: vmov.f32 s0, s1 @@ -276,8 +288,9 @@ define double @select_d(double %a, double %b, i1 %c) { ; CHECK-LABEL: select_d: -; NONE: ldr{{(.w)?}} [[REG:r[0-9]+]], [sp] -; NONE: ands [[REG]], [[REG]], #1 +; NOREGS: ldr{{(.w)?}} [[REG:r[0-9]+]], [sp] +; NOREGS: ands [[REG]], [[REG]], #1 +; ONLYREGS: ands r0, r0, #1 ; NOREGS-DAG: moveq r0, r2 ; NOREGS-DAG: moveq r1, r3 ; ONLYREGS-DAG: csel r0, r0, r2