This patch enables tail call optimization for long call on arm.
Previously we have too strict check on arm_function_ok_for_sibcall and be lack of the support on sibcall/sibcall_value expand that long call tail oppportunities are lost. OK for next next stage 1? thanks. -- Jiong gcc/ * config/arm/predicates.md (call_insn_operand): Add long_call check. * config/arm/arm.md (sibcall, sibcall_value): Force the address to reg for long_call. * config/aarch64/aarch64.c (arm_function_ok_for_sibcall): Remove long_call restriction. gcc/testsuite gcc.target/arm/tail-long-call.c: New test.
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c index d5f9ff3..8dcdfa8 100644 --- a/gcc/config/arm/arm.c +++ b/gcc/config/arm/arm.c @@ -6087,11 +6087,6 @@ arm_function_ok_for_sibcall (tree decl, tree exp) if (TARGET_VXWORKS_RTP && flag_pic && !targetm.binds_local_p (decl)) return false; - /* Cannot tail-call to long calls, since these are out of range of - a branch instruction. */ - if (decl && arm_is_long_call_p (decl)) - return false; - /* If we are interworking and the function is not declared static then we can't tail-call it unless we know that it exists in this compilation unit (since it might be a Thumb routine). */ diff --git a/gcc/config/arm/arm.md b/gcc/config/arm/arm.md index 2ddda02..fe285f0 100644 --- a/gcc/config/arm/arm.md +++ b/gcc/config/arm/arm.md @@ -9444,8 +9444,10 @@ "TARGET_32BIT" " { - if (!REG_P (XEXP (operands[0], 0)) - && (GET_CODE (XEXP (operands[0], 0)) != SYMBOL_REF)) + if ((!REG_P (XEXP (operands[0], 0)) + && GET_CODE (XEXP (operands[0], 0)) != SYMBOL_REF) + || (GET_CODE (XEXP (operands[0], 0)) == SYMBOL_REF + && arm_is_long_call_p (SYMBOL_REF_DECL (XEXP (operands[0], 0))))) XEXP (operands[0], 0) = force_reg (SImode, XEXP (operands[0], 0)); if (operands[2] == NULL_RTX) @@ -9462,8 +9464,10 @@ "TARGET_32BIT" " { - if (!REG_P (XEXP (operands[1], 0)) && - (GET_CODE (XEXP (operands[1],0)) != SYMBOL_REF)) + if ((!REG_P (XEXP (operands[1], 0)) + && GET_CODE (XEXP (operands[1], 0)) != SYMBOL_REF) + || (GET_CODE (XEXP (operands[1], 0)) == SYMBOL_REF + && arm_is_long_call_p (SYMBOL_REF_DECL (XEXP (operands[1], 0))))) XEXP (operands[1], 0) = force_reg (SImode, XEXP (operands[1], 0)); if (operands[3] == NULL_RTX) diff --git a/gcc/config/arm/predicates.md b/gcc/config/arm/predicates.md index ce5c9a8..3673343 100644 --- a/gcc/config/arm/predicates.md +++ b/gcc/config/arm/predicates.md @@ -673,5 +673,6 @@ (match_code "reg" "0"))) (define_predicate "call_insn_operand" - (ior (match_code "symbol_ref") + (ior (and (match_code "symbol_ref") + (match_test "!arm_is_long_call_p (SYMBOL_REF_DECL (op))")) (match_operand 0 "s_register_operand"))) diff --git a/gcc/testsuite/gcc.target/arm/tail-long-call.c b/gcc/testsuite/gcc.target/arm/tail-long-call.c new file mode 100644 index 0000000..9b27468 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/tail-long-call.c @@ -0,0 +1,12 @@ +/* { dg-skip-if "need at least armv5te" { *-*-* } { "-march=armv[234]*" "-mthumb" } { "" } } */ +/* { dg-options "-O2 -march=armv5te -marm" } */ +/* { dg-final { scan-assembler "bx" } } */ +/* { dg-final { scan-assembler-not "blx" } } */ + +int lcal (int) __attribute__ ((long_call)); + +int +dec (int a) +{ + return lcal (a); +}