Mercurial > hg > graal-jvmci-8
comparison src/cpu/x86/vm/macroAssembler_x86.cpp @ 24010:5aaa43d91c73
8063086: Math.pow yields different results upon repeated calls
Summary: C2 treats x^2 as a special case and computes x * x while the interpreter and c1 don't have special case code for X^2.
Reviewed-by: kvn
| author | csahu |
|---|---|
| date | Tue, 24 May 2016 17:49:06 +0530 |
| parents | daaf806995b3 |
| children | 371fd9bb8202 |
comparison
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| 24009:619e7d418a44 | 24010:5aaa43d91c73 |
|---|---|
| 3200 ffree(1); | 3200 ffree(1); |
| 3201 } | 3201 } |
| 3202 jmp(done); | 3202 jmp(done); |
| 3203 } else { | 3203 } else { |
| 3204 // Stack: X Y | 3204 // Stack: X Y |
| 3205 Label x_negative, y_odd; | 3205 Label x_negative, y_not_2; |
| 3206 | |
| 3207 static double two = 2.0; | |
| 3208 ExternalAddress two_addr((address)&two); | |
| 3209 | |
| 3210 // constant maybe too far on 64 bit | |
| 3211 lea(tmp2, two_addr); | |
| 3212 fld_d(Address(tmp2, 0)); // Stack: 2 X Y | |
| 3213 fcmp(tmp, 2, true, false); // Stack: X Y | |
| 3214 jcc(Assembler::parity, y_not_2); | |
| 3215 jcc(Assembler::notEqual, y_not_2); | |
| 3216 | |
| 3217 fxch(); fpop(); // Stack: X | |
| 3218 fmul(0); // Stack: X*X | |
| 3219 | |
| 3220 jmp(done); | |
| 3221 | |
| 3222 bind(y_not_2); | |
| 3206 | 3223 |
| 3207 fldz(); // Stack: 0 X Y | 3224 fldz(); // Stack: 0 X Y |
| 3208 fcmp(tmp, 1, true, false); // Stack: X Y | 3225 fcmp(tmp, 1, true, false); // Stack: X Y |
| 3209 jcc(Assembler::above, x_negative); | 3226 jcc(Assembler::above, x_negative); |
| 3210 | 3227 |