From 52057dc4ac5295caebf83147f688d769c93cbc8d Mon Sep 17 00:00:00 2001 From: Kyrylo Tkachov Date: Fri, 29 Jun 2018 13:36:35 +0000 Subject: [PATCH] [arm] Avoid STRD with odd register for TARGET_ARM in output_move_double In this testcase the user forces an odd register as the starting reg for a DFmode value. The output_move_double function tries to store that using an STRD instruction. But for TARGET_ARM the starting register of an STRD must be an even one. This is always the case with compiler-allocated registers for DFmode values, but the inline assembly forced our hand here. This patch restricts the STRD-emitting logic in output_move_double to not avoid odd-numbered source registers in STRD. I'm not a fan of the whole function, we should be exposing a lot of the logic in there to RTL rather than at the final output stage, but that would need to be fixed separately. * config/arm/arm.c (output_move_double): Don't allow STRD instructions if starting source register is not even. * gcc.target/arm/arm-soft-strd-even.c: New test. From-SVN: r262250 --- gcc/ChangeLog | 5 +++++ gcc/config/arm/arm.c | 22 ++++++++++++------- gcc/testsuite/ChangeLog | 4 ++++ .../gcc.target/arm/arm-soft-strd-even.c | 18 +++++++++++++++ 4 files changed, 41 insertions(+), 8 deletions(-) create mode 100644 gcc/testsuite/gcc.target/arm/arm-soft-strd-even.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 44012454e27..a76fea96782 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2018-06-29 Kyrylo Tkachov + + * config/arm/arm.c (output_move_double): Don't allow STRD instructions + if starting source register is not even. + 2018-06-29 Martin Liska PR tree-optimization/86263 diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c index c70be366ed8..f1a99588bab 100644 --- a/gcc/config/arm/arm.c +++ b/gcc/config/arm/arm.c @@ -18463,12 +18463,18 @@ output_move_double (rtx *operands, bool emit, int *count) gcc_assert ((REGNO (operands[1]) != IP_REGNUM) || (TARGET_ARM && TARGET_LDRD)); + /* For TARGET_ARM the first source register of an STRD + must be even. This is usually the case for double-word + values but user assembly constraints can force an odd + starting register. */ + bool allow_strd = TARGET_LDRD + && !(TARGET_ARM && (REGNO (operands[1]) & 1) == 1); switch (GET_CODE (XEXP (operands[0], 0))) { case REG: if (emit) { - if (TARGET_LDRD) + if (allow_strd) output_asm_insn ("strd%?\t%1, [%m0]", operands); else output_asm_insn ("stm%?\t%m0, %M1", operands); @@ -18476,7 +18482,7 @@ output_move_double (rtx *operands, bool emit, int *count) break; case PRE_INC: - gcc_assert (TARGET_LDRD); + gcc_assert (allow_strd); if (emit) output_asm_insn ("strd%?\t%1, [%m0, #8]!", operands); break; @@ -18484,7 +18490,7 @@ output_move_double (rtx *operands, bool emit, int *count) case PRE_DEC: if (emit) { - if (TARGET_LDRD) + if (allow_strd) output_asm_insn ("strd%?\t%1, [%m0, #-8]!", operands); else output_asm_insn ("stmdb%?\t%m0!, %M1", operands); @@ -18494,7 +18500,7 @@ output_move_double (rtx *operands, bool emit, int *count) case POST_INC: if (emit) { - if (TARGET_LDRD) + if (allow_strd) output_asm_insn ("strd%?\t%1, [%m0], #8", operands); else output_asm_insn ("stm%?\t%m0!, %M1", operands); @@ -18502,7 +18508,7 @@ output_move_double (rtx *operands, bool emit, int *count) break; case POST_DEC: - gcc_assert (TARGET_LDRD); + gcc_assert (allow_strd); if (emit) output_asm_insn ("strd%?\t%1, [%m0], #-8", operands); break; @@ -18513,8 +18519,8 @@ output_move_double (rtx *operands, bool emit, int *count) otherops[1] = XEXP (XEXP (XEXP (operands[0], 0), 1), 0); otherops[2] = XEXP (XEXP (XEXP (operands[0], 0), 1), 1); - /* IWMMXT allows offsets larger than ldrd can handle, - fix these up with a pair of ldr. */ + /* IWMMXT allows offsets larger than strd can handle, + fix these up with a pair of str. */ if (!TARGET_THUMB2 && CONST_INT_P (otherops[2]) && (INTVAL(otherops[2]) <= -256 @@ -18579,7 +18585,7 @@ output_move_double (rtx *operands, bool emit, int *count) return ""; } } - if (TARGET_LDRD + if (allow_strd && (REG_P (otherops[2]) || TARGET_THUMB2 || (CONST_INT_P (otherops[2]) diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index c7fef19358d..9072c6d5dd6 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2018-06-29 Kyrylo Tkachov + + * gcc.target/arm/arm-soft-strd-even.c: New test. + 2018-06-29 Tom de Vries * gcc.dg/guality/pr45882.c (foo): Add line number var for breakpoint diff --git a/gcc/testsuite/gcc.target/arm/arm-soft-strd-even.c b/gcc/testsuite/gcc.target/arm/arm-soft-strd-even.c new file mode 100644 index 00000000000..fb7317c8718 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/arm-soft-strd-even.c @@ -0,0 +1,18 @@ +/* { dg-do assemble } */ +/* { dg-require-effective-target arm_arm_ok } */ +/* { dg-options "-O2 -marm -mfloat-abi=soft" } */ + +/* Check that we don't try to emit STRD in ARM state with + odd starting register. */ + +struct S { + double M0; +} __attribute((aligned)) __attribute((packed)); + +void bar(void *); + +void foo(int x, struct S y) { + asm("" : : : "r1", "r8", "r7", "r4"); + y.M0 ?: bar(0); + bar(__builtin_alloca(8)); +} -- 2.30.2