diff options
Diffstat (limited to 'gcc/reg-stack.c')
| -rw-r--r-- | gcc/reg-stack.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/gcc/reg-stack.c b/gcc/reg-stack.c index 89a7a11e0bc..c931349f0f4 100644 --- a/gcc/reg-stack.c +++ b/gcc/reg-stack.c @@ -97,6 +97,9 @@ All implicitly popped input regs must be closer to the top of the reg-stack than any input that is not implicitly popped. + All explicitly referenced input operands may not "skip" a reg. + Otherwise we can have holes in the stack. + 3. It is possible that if an input dies in an insn, reload might use the input reg for an output reload. Consider this example: @@ -461,6 +464,7 @@ check_asm_stack_operands (rtx_insn *insn) char reg_used_as_output[FIRST_PSEUDO_REGISTER]; char implicitly_dies[FIRST_PSEUDO_REGISTER]; + char explicitly_used[FIRST_PSEUDO_REGISTER]; rtx *clobber_reg = 0; int n_inputs, n_outputs; @@ -568,6 +572,7 @@ check_asm_stack_operands (rtx_insn *insn) popped. */ memset (implicitly_dies, 0, sizeof (implicitly_dies)); + memset (explicitly_used, 0, sizeof (explicitly_used)); for (i = n_outputs; i < n_outputs + n_inputs; i++) if (STACK_REG_P (recog_data.operand[i])) { @@ -581,6 +586,8 @@ check_asm_stack_operands (rtx_insn *insn) if (j < n_clobbers || op_alt[i].matches >= 0) implicitly_dies[REGNO (recog_data.operand[i])] = 1; + else if (reg_class_size[(int) op_alt[i].cl] == 1) + explicitly_used[REGNO (recog_data.operand[i])] = 1; } /* Search for first non-popped reg. */ @@ -600,6 +607,23 @@ check_asm_stack_operands (rtx_insn *insn) malformed_asm = 1; } + /* Search for first not-explicitly used reg. */ + for (i = FIRST_STACK_REG; i < LAST_STACK_REG + 1; i++) + if (! implicitly_dies[i] && ! explicitly_used[i]) + break; + + /* If there are any other explicitly used regs, that's an error. */ + for (; i < LAST_STACK_REG + 1; i++) + if (explicitly_used[i]) + break; + + if (i != LAST_STACK_REG + 1) + { + error_for_asm (insn, + "explicitly used regs must be grouped at top of stack"); + malformed_asm = 1; + } + /* Enforce rule #3: If any input operand uses the "f" constraint, all output constraints must use the "&" earlyclobber. @@ -607,7 +631,7 @@ check_asm_stack_operands (rtx_insn *insn) record any earlyclobber. */ for (i = n_outputs; i < n_outputs + n_inputs; i++) - if (op_alt[i].matches == -1) + if (STACK_REG_P (recog_data.operand[i]) && op_alt[i].matches == -1) { int j; |